Science.gov

Sample records for pond dam study

  1. Seismic analysis of the Par Pond Dam: Study of slope failure and liquefaction. Technical evaluation report

    SciTech Connect

    Simos, N.; Reich, M.

    1994-07-01

    Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.

  2. 5. UPSTREAM (WEST) VIEW OF SPILLWAY, WITH COOKE DAM POND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. UPSTREAM (WEST) VIEW OF SPILLWAY, WITH COOKE DAM POND IN FOREGROUND AND NORTH EMBANKMENT (MI-98-A) AT LEFT. VIEW TO NORTHEAST. - Cooke Hydroelectric Plant, Spillway, Cook Dam Road at Au Sable River, Oscoda, Iosco County, MI

  3. 10. VIEW OF THE SEDIMENT DAM AND POND, FACING SOUTH. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW OF THE SEDIMENT DAM AND POND, FACING SOUTH. PHOTO TAKEN FROM WATER PUMP (FEATURE B-25). - Nevada Lucky Tiger Mill & Mine, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  4. Hydraulic and hydrologic evaluation of PAR Pond Dam. Technical evaluation report

    SciTech Connect

    Reich, M.; Wang, P.C.; Khanbilvardi, R.; Bezler, P.

    1993-10-01

    The PAR Pond Dam at Savannah River Plant was constructed in 1958--1959. Seepage, depressions, boils and spring flow were observed in varying locations on the dam in the last few years. Comprehensive geotechnical and hydraulic investigations pertaining to the effects of the above observations on the abilities of the dam to withstand future floods were made in 1991 and early 1993 where dam capacity to survive flooding and seismic events were evaluated. Brookhaven National Laboratory (BNL) was asked by the Department of Energy (EH) to carry out an independent review of the PAR Pond Dam response to future flooding and seismic events. This report addresses the studies made to evaluate the capacity of the dam to survive floods. A companion report will summarize the evaluations performed to assess the seismic capacity of the dam.

  5. COOKE DAM POND AND UPSTREAM (WEST) SIDE OF (LR) NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    COOKE DAM POND AND UPSTREAM (WEST) SIDE OF (L-R) NORTH EMBANKMENT (MI-98-A), SPILLWAY (MI-98-B), PENSTOCK ENTRANCES, POWERHOUSE (MI-98-C), AND SOUTH EMBANKMENT (MI-98-E). VIEW TO NORTHEAST - Cooke Hydroelectric Plant, Cook Dam Road at Au Sable River, Oscoda, Iosco County, MI

  6. Surface and subsurface soils at the Pond B dam: July 1998

    SciTech Connect

    Halverson, N.V.

    1999-12-03

    Pond B, 685-13G, is an inactive reactor cooling impoundment built in 1961 on the Savannah River Site (SRS). Between 1961 and 1964, Pond B received R-Reactor cooling water discharges that were contaminated with {sup 137}Cs, {sup 90}Sr and plutonium. Though the pond has not been used since 1964, radionuclides from the contaminated cooling water remain in the water and in the surface sediments of the pond. The current proposal to fix and repair the Pond B dam structure includes installing a new drain system and monitoring equipment. The dam will be reinforced with additional previous material on the downstream face of the dam. The objectives of this report are to describe the sampling methodology used during the July 1998 sampling event at the downstream face of the Pond B dam and in Pond B, present the results of the sampling event, and compare, where possible, these results to related risk-based standards.

  7. Estimation of Downstream Cesium Concentrations Following a Postulated PAR Pond Dam Break

    SciTech Connect

    Chen, K.F.

    2002-07-08

    Following a postulated PAR Pond dam break, some of the PAR Pond sediment including the cesium could be eroded and be transported downstream to the Savannah River through the Lower Three Runs Creek. Studies showed that most of the eroded sediment including the cesium would deposit in the Lower Three Runs Creek and the remainder would discharge to the Savannah River from the mouth of Lower Three Runs Creek. A WASP5 model was developed to simulate the eroded sediment and cesium transport from the Lower Three Runs Creek mouth to the Atlantic coast. The dissolved cesium concentrations at the Highway 301 bridge and near the City of Savannah Industrial and Domestic Water Supply Plant are 30 and 27 pCi/l, respectively. The concentrations at both locations are less than the U. S. Environmental Protection Agency drinking water standard of 200 pCi/l.

  8. National Program for Inspection of Non-Federal Dams. Ames Pond Dam (MA 01006) Dike A (MA 01296) Merrimack River Basin, Tewksbury, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1980-12-01

    Massachusetts 02146 . Copies of this report will be made available to the public, upon request to this office, under the Freedom of Information Act...Ownership. Ames Pond Dam is owned by the Beacon Mortgage, Inc. 1425 Beacon St., Brookline, MA 02146 . Tele: 617-232-7850. An Engineering Report shown...Brookline, MA 02146 . Tele: 617-232-7850. g. Purpose of Dam. The dam impounds a pond used for recreational purposes. 3

  9. National Program for Inspection of Non-Federal Dams. Miles Pond Dam (VT 00062), Connecticut River Basin, Concord, Vermont. Phase I Inspection Report.

    DTIC Science & Technology

    1980-12-01

    d0ifyY &Y Use& OARJ THe dam is an earth embankment with a concrete outlet structure and emergency spillway about in the center of the dam. It is 19 ft...Stream: Miles Pond Brook Date of Inspection: September 30, 1980 Miles Pond Dam is an earth embankment with a concrete outlet structure and emergency...impoundment of water for recreational use. The appurtenant works consist of a stop log chute spillway, an emergency spillway, and a concrete

  10. National Program for Inspection of Non-Federal Dams. Hattertown Pond Dam (CT 00313), Connecticut Coastal Basin, Newtown, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-05-01

    n:ceeeetay 40 i11011l F block Mitor) The existing Hattertown Pond Dam consists of an earth and rockfill dam approximatel, 95 feet long, 11 feet high and 8 feet...Hattertown Pond Dam consists of an earth and rockfill dam approximately 95 feet long, 11 feet high and 8 feet wide at the crest. A 19-foot-long...undertake the same, as enumerated below: 1. The site will be cleared of fallen branches of trees, roots, stumps, dislodged boulders, etc. 2. The earth dam

  11. National Program for Inspection of Non-Federal Dams. Nichols Pond Dam (VT 00184), Richelieu River Basin, Woodbury, Vermont. Phase I Inspection Report.

    DTIC Science & Technology

    1980-04-01

    on pages B-12 through B-14. A letter report by ’fr. Barranco describes some of the history on page B-15. 3. Plans and sketches prepared by DuBois...Peter Barranco , Jr., P.E., Dam Safety Engineer I Subject: Nichols Pond Dam - Woodbury (252-1) The writer inspected subject dam, obtained dimensions and

  12. National Program for Inspection of Non-Federal Dams. Lee’s Pond Dam (CT 00061), Saugatuck River Basin, Westport, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1980-09-01

    14 5.4 Test Flood Analysis ....... ................ 14 5.5 Dam Failure Analysis ................... 15 6. EVALUATION OF...Classification - Lee’s Pond Dam is classified as having a low hazard potential. Failure of the dam should not cause any loss of life or property damage...Just prior to failure (water level at top of dam), the estimated flow and water depths several hundred feet downstream are 8,800 cfs at 8 feet and

  13. National Program for Inspection of Non-Federal Dams. Bickford Pond Dam (MA 01021), Bickford Reservoir Dam (MA 01022), Connecticut River Basin, Hubbardston and Princeton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1980-06-01

    long earth dam with concrete core wall. The dam has a maximum height of 51.2 feet and includes a drop inlet spillway and box conduit outlet structure...spillway. Bickford Reservoir Dam , also known as the Bickford Dike, was built in 1970 and is a 507-foot long earth dam with a concrete core wall. The dam ...deg. 56.1 min. I west. b. Description of Dams and Appurtenances. Bickford Pond Dam is a 933-foot long, earth embankment dam with a 15-inch thick

  14. National Program for Inspection of Non-Federal Dams, Harrisville Pond Dam (NH 00065), Merrimack River Basin, Harrisville, New Hampshire. Phase I Inspection Report.

    DTIC Science & Technology

    1979-05-01

    a maximum height of *21 ft. and is about 75 ft. long. The dam is judged to be in fair conditon . * It is intermediate in size with a high hazard...The preliminary hydrologic analysis has indicated that the spillway -.- capacity for the Harrisville Pond Dam would likely be exceeded by floods ...greater than 2.5 percent of the Probable Maximumr Flood (?’IF), the test flood for spillway adequacy. Our screening criteria specifies that a dam of this

  15. National Program for Inspection of Non-Federal Dams. Manchaug Pond Dam MA 00955, Blackstone River Basin, Sutton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1980-07-01

    low spillage facility used for recreational purposes and for the storage of water for industrial use by mills located downstream of the dam. The...community and industrial economic loss, with the potential for the loss of more than a few lives. e. Ownership. Manchaug Pond Dam is owned by the...County Ensineer -,--.---- TOWN _. -’ DAM NO. LOCATION . -- A’-’ STREAM _ __ __._ f WORCESTER COUNIT EmGINEERING DEPARTMENTWORCESTER, MASSAC HUSETTS RAM

  16. National Program for Inspection of Non-Federal Dams. Batterson Park Pond Dam (CT 00262), Connecticut River Basin, Farmington/New Britain, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1978-12-01

    inflow into the reservoir is 8,892 cfs (1,900 cfs/sm x 4.68 sm). However, just upstream of Batterson Park Pond is Dead Wood Swamp which controls 1.98...Batterson Park Pond Dam DATE 9-28-.78 pR C tTATUE_____MW______ R. Aloma I I SCPLIP _________WNW____ G. Giroux ARE~A EVALUATED CONDITIO14 I OWLET WORKs - S745

  17. National Dam Inspection Program. Bronson Pond Dam (NDI ID Number PA 00143, DER ID Number 64-42),Delaware River Basin, Middle Creek, Wayne County, Pennsylvania. Phase I Inspection Report.

    DTIC Science & Technology

    1981-02-01

    r Bronson Pond Dam is an earth and rockfill structure approxi- mately 8 feet high and 100 feet in length. The dam was...near top of dam . Inflow occurring when the lake is at or above top of dam passes over and through the rockfill embankment. 1.3 Pertinent Data. a...the dam could cause a gradual, progressive failure. The flow rate does not appear to be an excessive amount for a dam of rockfill construction, but

  18. National Program for Inspection of Non-Federal Dams. Sawyer Pond Dam (MA 00050), Connecticut River Basin, Northfield, Massachusetts.

    DTIC Science & Technology

    1981-03-01

    of the upstream retaining walls could lead to slope instability. The dam has a low-level outlet consisting of two, four-inch diameter taps with valves...comnputational evaluations are beyond the scope of a Phase I investigation: however, the investigation is intended to identify any need for such studies. In...b. Purpose of InspecLion. The purpose of performing technical inspections and evaluation of non-federal dams is to : 1. Identify conditions which

  19. National Program for Inspection of Non-Federal Dams. Bigney Pond Dam (MA 00422), Massachusetts-Rhode Island Coastal Basin, Brockton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1978-12-01

    Top .’A Classification of Dam by Material: Earth Conc. Masonry ’ .. Stone 1Mason. i.- Timh~er - Rockfill O-het a...length of earth embankment confined by vertical stone masonry retaining walls about 11 ft. high. The crest of the dam is Torrey Street, a paved secondary...AD-Ri54 498 NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERRL DRMS 1/1 BIGNEY POND DAM (HA 9..(U) CORPS OF ENGINEERS MALTHAM N A NEW ENGLAND DIV DEC 78

  20. National Program for Inspection of Non-Federal Dams, Gorton Pond Dam (CT 00157), Connecticut Coastal Basin, East Lyme, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-01-01

    12.5’ West Longitude as shown on the Niantic , CT, USGS quadrangle sheet. The dam impounds water from the Pataguanset River which drains a 6.7 square...provide power for Niantic Mills at the dam site. Some time later ownership of the dam passed to the New England Steam Gauge Co., went out of commercial...INSPECTION BY A. J. MACCHI, ENGINEERS V. ON MARCH 15, 1963 *This pond is located on the Patagansett River about -one mile north of the town of Niantic

  1. National Dam Safety Program. Green Turtle Pond Dam (NJ00190), Passaic River Basin, Branch of Wanaque River, Passaic County, New Jersey. Phase I Inspection Report.

    DTIC Science & Technology

    1980-02-01

    NUMBER NJ00190 4. TITLE (and SubtI.j) S. TYPE OF REPORT & PERIOD COVERED ational Dam Safet Proi 7 amNA L C Green Turtle Pond lam NJ0096!f"W "AFMTkM 4I...report, the owner should develop written operating procedures and a periodic maintenance plan to ensure the safety of the dam. A copy of the report is...owner should develop written operating procedures and a periodic maintenance plan to ensure the safety of the dam.- APPROVED: _____________ "AMES G

  2. National Dam Safety Program. Alder Pond Dam (Inventory Number N.Y. 1489), Black River Basin, Oneida County, New York. Phase I Inspection Report,

    DTIC Science & Technology

    1981-06-17

    HYDRAULIC ENGINEERING DATA AND COMPUTATIONS ALDEA , POND4 MA CHECK LIST FOR DAMS ~1B HYDROLOGIC AND HYDRAULIC ENGINEERING DATA AREA-CAPACITY DATA...Releases (mechanisms): 90KI5- 93-15=a , 9/8o)? ALDEA Pom P VAtA - 1489 DRAINAGE AREA: 55(p ACE 5.18 ’SQ IbILEb5 DRAINAGE BASIN RUNOFF CHARACTERISTICS

  3. Synthesizing Studies of Dam Removal

    NASA Astrophysics Data System (ADS)

    O'Connor, Jim; East, Amy

    2014-10-01

    Dam decommissioning is rapidly emerging as an important river restoration strategy in the United States. Hundreds of dams have been removed in the past few decades, including several large ones (>10-15 meters) impounding large sediment volumes (>106 cubic meters) in the past 3 years, notably Condit Dam and the Elwha River dams in Washington State. These removals and the associated studies provide for the first time an opportunity to evaluate the immediate and persistent consequences of these significant fluvial—and in some cases, coastal—perturbations. Understanding dam removal response not only improves understanding of landscape and ecosystem adjustment to profound sediment pulses but also provides important lessons for future watershed restoration efforts.

  4. National Dam Inspection Program. Saxe Pond Dam (NDI I.D. Number PA-729, DER ID Number 8-10) Susquehanna River Basin. North Branch Mehoopany Creek, Bradford County, Pennsylvania. Phase I Inspection Report,

    DTIC Science & Technology

    1981-04-01

    formations and the Catskill Formation between them belong to the Susquehanna Group of Upper Devonian Age. They consist of sandstones, shales , and...1; 1. I)If *~~~~~ C iy GEOLOGIC MAP OF AREA AROUND SAXE POND DAM, ROSCOE BURGESS DAM AND THE BIRCH CREEK DAM SCALE 1:250,000 PENNSvVANIAN DEVONIAN

  5. National Program for Inspection of Non-Federal Dams. Georgiaville Pond Dam (RI 03108), Woonasquatucket River Basin, Smithfield, Rhode Island. Phase I Inspection Report.

    DTIC Science & Technology

    1979-04-01

    with concrete and the structure is abandoned. - 0 0 A0 5 -7 7 07.71 PERIODIC INSPECTION CHECK LIST *PROJECT Georgi avilIlIe Pond Dam DATE November 30...VISUAL INSPECTION CHiECK LIST * PARTY ORGANIZATiON PROJECT Georgi avil11e Pond flam DATE November 30. 1978 * Smithfield, RI* 6 TIME 8AM to 3PM wEATHER...Deow Hr. Bloyd: fot ihode Island. I visited the Georiaville Dm an October 4, 1968 in company with you, Hr. Howard and Mr. Chawles Rap linger of the

  6. WMOST v2 Case Study: Monponsett Ponds

    EPA Science Inventory

    This webinar presents an overview of the preliminary results of a case study application of EPA's Watershed Management Optimization Support Tool v2 (WMOST) for stakeholders in the Monponsett Ponds Watershed Workgroup. Monponsett Ponds is a large water system consisting of two ba...

  7. WMOST v2 Case Study: Monponsett Ponds

    EPA Science Inventory

    This webinar presents an overview of the preliminary results of a case study application of EPA's Watershed Management Optimization Support Tool v2 (WMOST) for stakeholders in the Monponsett Ponds Watershed Workgroup. Monponsett Ponds is a large water system consisting of two ba...

  8. National Program for Inspection of Non-Federal Dams. Merino Pond Dam (MA 00110), Thames River Basin, Dudley, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-09-01

    soot",0 ftsoauetts 02133 Der Governor Kng: inclosed Is a copy of the "ari. Pond Dam Phase I Inspect ion Report, which was prepared under the Vational...C S S 5 PREFACE This report Is prepared under guidance contained in the Recommended Guide- * lines for Safety Inspection of Dams, for Phase I... Pectinent Data 1-. 2. ENCINLU.RtG DATA 2.1 Design 2-1 2.2 Construction 2-1 F m2.3 operati|on 2-1r 2.4 Evaluation 2-1 3. VISUAL. INSPECTION 3.1

  9. National Program for Inspection of Non-Federal Dams. Colton Pond Dam VT 00114, Connecticut River Basin, Sherburne, Vermont. Phase I Inspection Report.

    DTIC Science & Technology

    1979-10-01

    by the State of Vermont Fish and Game Department. The State’s Dam Safety Engineer is Mr. A. Peter Barranco , Jr., P.E. Mr. Barranco is located at the...PARTY: * 1. D. LaGatta GEl 6 2. S. Mazur HNTB 7. 3. R. Yarsites HNTB 8. 4. Peter Barranco Jr. VDWR 9. ii5. 10.0 *PROJECT FEATURE INSPECTED BY EMARKS 1...Commissioner, Fish &’Game Fr -FOM: A. Peter Barranco , Jr. ,. Environmental Engineer Subject: Colton’Pond Dam -Sherburne On September 28 the writer made a

  10. National Dam Safety Program. Barbours Pond Dam (NJ00241) Passaic River Basin, Slippery Rock Brook, Passaic County, New Jersey. Phase I Inspection Report.

    DTIC Science & Technology

    1981-03-01

    at this location consists of basalt originally laid down as a lava flow during the Triassic period . This hard, fine grained igneous rock provides an...NO. RECIPIENTS CATALOG #EUMUER C9 i i 5. Type OiF REPORT a PERIOD COVERED NatinalDan afey Pr o~F~m tneowtm fFINAL rQA ( Barbours Pond DamJ tZ . UI 0...should develop written operating procedures and a periodic maintenance plan to ensure the safety of the dam within one year from the date of approval of

  11. Arsenic concentrations in soils impacted by dam failure of coal-ash pond in Zemianske Kostolany, Slovakia.

    PubMed

    Jurkovič, L'ubomír; Hiller, Edgar; Veselská, Veronika; Pet'ková, Katarína

    2011-04-01

    In this study, the concentrations of arsenic were determined in the soils around old coal-ash pond. The soils in the study area were severely contaminated with arsenic after dam failure of the coal-ash pond. The mean concentrations of arsenic in soils collected from three sampling depths of 0-20, 20-40 and >40 cm were 173, 155 and 426 μg/g, respectively, exceeding greatly the Dutch intervention threshold for this element. Arsenic concentrations were positively correlated with total iron and aluminium contents in the soils (r = 0.73, p < 0.001 and r = 0.72, p < 0.001, respectively), indicating that oxyhydroxides of iron and aluminium may control the distribution of arsenic in these soils. Ammonium nitrate extractant was used to mimic availability of arsenic for plant uptake from the soils. Between 0.05 and 6.21% of the total soil arsenic were extracted using a single extraction test and a significant positive correlation between soil leachate pH and arsenic extractability (r = 0.70, p < 0.01) was observed. This suggested that soil pH might play a role in the bioavailability of arsenic.

  12. National Program for Inspection of Non-Federal Dams. Norton Pond Dam (VT 00198), St. Francis River Basin, Norton, Vermont. Phase I Inspection Report.

    DTIC Science & Technology

    1979-01-01

    Federal Dams. This report is presented for your use and is based upon a visual inspection, a review of the past performance and a brief-. hydrological study...upstream of the dam and downstream channel obstruction caused by overhanging trees and brush. Based on the dam’s intermediate size and significant...The assessment of the general con- dition of the dam is based upon available data and visual inspections. Detailed investigation and analyses

  13. National Program for Inspection of Non-Federal Dams. Upper Bemis Pond Dam (MA 00069), Lower Bemis Pond Dam (MA 00531), Connecticut River Basin, Chicopee, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1980-10-01

    includes drainage from UCpper Bemis Pond; an-, difrect Jrin age amounting to 14 acres. I n f-e nera 1, h e u ndJ--evel-: ,> portions of the drainage...to2 the 1.2 ’ sqcuare 71le drainag-e area results in a - etest flod inflow -: 1,0-30 cfs. By adl usting thie test flood inl;’ fr su-_; charge storare...VisiLl : R infci’ci:g R/H wall top in spalled area Any 2S’p; age or Ffflorw2c(%nce None Drain Holes None c. -sc ar’gt Channel Grass covered slope of dam

  14. South Bay Salt Pond Mercury Studies Project

    EPA Pesticide Factsheets

    Information about the SFBWQP South Bay Salt Pond Mercury Studies Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  15. National Program for Inspection of Non-Federal Dams. Park Pond Dam (CT 00632), Dike (CT 01708), Naugatuck River Basin, Winchester, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-03-01

    RnI. D iI ES FAD I N , SHEET NO .3 OF.10 • C(0 KID BY.S f - CONSULTING ENGINEER S JOB NO,. 014.’.9 039 SUBJECT PARK POND DAM -F LOOD ROUT ING AT C)P OF...OF [’AM SECTION NUMBER 6C 0 RIGHT OVERBANK H WA RSV (FT) (FT) ! ,SO-T) (FT) (F T/ Ft F ; E C") c s) 40 72 0. 2! . 0 3179 u 79 1 5. 0 20 1 0.75~ 0.0179

  16. Environmental Assessment and Finding of No Significant Impact: Pond B Dam Repair Project at the Savannah River Site

    SciTech Connect

    N /A

    1999-09-27

    The Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-1285) for the proposed repair of the Pond B dam at the Savannah River Site (SRS), located near Aiken, South Carolina. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an environmental impact statement (EIS) is not required, and DOE is issuing this Finding of No Significant Impact (FONSI) and Floodplain Statement of Findings.

  17. CERCLA interim action at the Par Pond unit: A case study

    SciTech Connect

    Hickey, H.M.; Matthews, S.S.; Neal, L.W.; Weiss, W.R.

    1993-11-01

    The Par Pond unit designated under CERCLA consists of sediments within a Savannah River Site (SRS) cooling water reservoir. The sediments are contaminated with radionuclides and nonradioactive constituents from nuclear production reactor operations. The mercury in Par Pond is believed to have originated from the Savannah River. Because of Par Pond Dam safety Issues, the water level of the reservoir was drawn down, exposing more than 1300 acres of contaminated sediments and triggering the need for CERCLA interim remedial action. This paper presents the interim action approach taken with Par Pond as a case study. The approach considered the complexity of the Par Pond ecosystem, the large size of Par Pond, the volume of contaminated sediments, and the institutional controls existing at SRS. The Environmental Protection Agency (EPA) considers units with large volumes of low-concentration wastes, as is the case with Par Pond, to be {open_quotes}special sites.{close_quotes} Accordingly, EPA guidance establishes that the range of alternatives developed focus primarily on containment options and other remedial approaches that mitigate potential risks associated with the {open_quotes}special site.{close_quotes} The remedial alternatives, according to EPA, are not to be prohibitively expensive or difficult to implement. This case study also is representative of the types of issues that will need to be addressed within the Department of Energy (DOE) complex as nuclear facilities are transitioned to inactive status and corrective/remedial actions are warranted.

  18. Evaporation Ponds or Recharge Structures ? the Role of Check Dams in Arkavathy River Basin, India

    NASA Astrophysics Data System (ADS)

    Jeremiah, K.; Srinivasan, V.; R, A.

    2014-12-01

    "Watershed development" has been the dominant paradigm for water management in India for the last two decades. Current spending on watershed development programmes rivals spending on large dams. In practice, watershed development involves a range of soil and water conservation measures including building check dams, gully plugs, contour bunds etc. Despite their dominance in water management paradigms, relatively little empirical data exists on these structures. Importantly, even though the benefits of individual watershed structures are recognized, the cumulative impact of building hundreds of such structures on hydrologic partitioning of a watershed remains unknown. We investigated the role of check dams in two small milli-watersheds in the Arkavathy River basin in South India. We conducted a comprehensive census of all check dams in the two milli-watersheds with a total area of 26 sq km. 40 check dams (representing a density of 1.35/sq km of watershed area) were geotagged, photographed, measured and their condition was recorded. We then selected twelve check dams and monitored the water stored using capacitance sensors. We also set up Automatic Weather Stations in each watershed. Inflows, evaporation and infiltration were calculated at each site to evaluate how check dams alter hydrologic partitioning in the watershed as a whole.

  19. National Program for Inspection of Non-Federal Dams. West Pond Outlet (MA 00186), Massachusetts Coastal Basin, Gloucester, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-12-01

    and ask that you keep me informed of the actions taken to implement them. This follow- up action is a vitally important part of this program. A copy of...clut- tered up with rubbish. The spillway is three feet below the top of the dam. The lower side of the dam is wet and looks like there is leakage. The...ly behind it. The pond is full and ovefflowing, so practically none of stone wall from up -stream side of dam can be seen. Unless spillvay is to be

  20. National Dam Inspection Program. Johnson’s Pond (NDI-ID Number MD-11), Wicomico River Basin, Wicomico River, Wicomico County, Maryland. Phase I Inspection Report,

    DTIC Science & Technology

    1980-07-01

    include construction records or design calculations for the clay fill embankments, is considered to be sufficient to make the recommendations that are...DAM INSPECTION PROGRAM JOHNSONIS POND SCALE GUIDE TO LOCATION OF PHOTOGRAPHS 0 50’ 100, __________________________________ 11E 1980 PLATE C-1 I~ EhI

  1. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    NASA Astrophysics Data System (ADS)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  2. 33 CFR 208.27 - Fort Cobb Dam and Reservoir, Pond (Cobb) Creek, Oklahoma.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., flows shall not exceed a 13.0-foot stage (1,300 cfs) on the USGS gage on Pond (Cobb) Creek near Fort Cobb, Oklahoma, river mile 5.0; a 19.0-foot stage (6,000 cfs) on the USGS gage on the Washita River near Anadarko, Oklahoma, river mile 305.0; or a 19.0-foot stage on the USGS gage near Bradley, Oklahoma...

  3. National Program for Inspection of Non-Federal Dams. Lyman Mill Pond (MA 00500), Connecticut River Basin, Southampton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-03-01

    117 AD-Ri54 955 NATIONAL PRbGRAM FOR INSPECTION OF NON-FEDERAL DAMS in. LYMAN HILL POND (MA B..(U) CORPS OF ENGINEERS WALTHRM MR NEW ENGLAND DIV MAR...INSPECTION REPORT NATIONAL DAM INSPECTION PROGRAM ~DTI9 * - c#) QELECTE LUJ . DEPARTMENT OF THE ARMY NEW ENGLAND DIVISION, CORPS OF ENGINEERS WALTHAM, MASS...PERFORMINGONRG. REPORT NUMBER 7 AUTiHOHfa) 9. CONTRACT OR GRANT NUMBER(@) U.S. ARMY CORPS OF ENGINEERS NEW ENGLAND DIVISION 9 PERFORMING ORGANIZATION NAME AND

  4. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  5. Dam water quality study. Report to Congress

    SciTech Connect

    Not Available

    1989-05-01

    The objective of the report is to identify water quality effects attributable to the impoundment of water by dams as required by Section 524 of the Water Quality Act of 1987. The document presents a study of water quality effects associated with impoundments in the U.S.A.

  6. National Program for Inspection of Non-Federal Dams. Upper Porter Pond Dam MA 00425, Taunton River Basin, Brockton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1980-01-01

    the downstream toe of the dam . The slope is partially covered with grass with areas of rock fill and bare earth . Several small trees are growing on the... Dam 19 Test Flood Pool 21 1-4 L.. • ... * g. Dam Data. Type Earth embankment Length34f e+ Top Width 80 feet + *Side Slopes (Upstream) 3H:1V (Downstream... Dam : Length 3.__ _ Max. Height JJ Slopes: Upstream Face J4 Downstream Face 6 Width Across Top ___(__ 83. Classification of Dam by Material: Earth

  7. National Program for Inspection of Non-Federal Dams. Grafton Pond Dam (NH 00119) NHWRB 96.01, Connecticut River Basin, Grafton, New Hampshire. Phase I Inspection Report.

    DTIC Science & Technology

    1978-11-01

    training of local officials in dam operations to decrease response time in operating the dam in the event of an emergency. The structural...horizontal cracks, seepage, leaching, stalactites , exudation, , and encrustation. In general, the horizontal cracks ..... are located in well defined...erosion, disintegra- --- - tion, scaling, leaching, stalactites , exudation and encrustation. The deteriorated condition of these structural

  8. 76 FR 12094 - Whitman River Dam, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ..., 38.5-foot-high Crocker Pond dam; (2) an existing 99.7- acre impoundment with a normal water surface... Federal Energy Regulatory Commission Whitman River Dam, Inc. Notice of Application Tendered for Filing With the Commission and Soliciting Additional Study Requests Take notice that the...

  9. National Dam Inspection Program. Jennings Pond Dam (NDI I.D. PA-0891 DER I.D. 066-012) Susquehanna River Basin, Little Mehoopany Creek, Wyoming County, Pennsylvania. Phase I Inspection Report,

    DTIC Science & Technology

    1981-03-19

    CdeS ii i~ Aval i and/’r--PC ieesah r Assessment - Jennings Pond Dam 3. Around-the-clock surveillance should be provided during unusually heavy runoff...of upstream rock fill is unknown Cutoff Concrete wall Grout curtain Unknown h. Regulating Outlet Type 22-inch pipe Length 50+ feet Closure Upstream...concrete conduit controlled by a gate on the upstream end. A stem supported by a steel structure is used to manually operate the gate. The pipe extends

  10. National Program for Inspection of Non-Federal Dams. Halchek Pond Dam (CT 00677), Shetucket River Basin, Willington, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-03-01

    and sunny and the ground was clear of snow . As a result of the visual inspection, a review of the history , and general appearance, the dam at Hal- chek...conditions, and is evolutionary in nature. It would be incorrect to assume that the present condition of the dam will continue to represent the condition of...Project 0 h. Design and Construction History i. Normal Operational Procedures 1.3 Pertinent Data 4 a. Drainage Area 0 b. Discharge at Dam Site c. Elevations

  11. National Program for Inspection of Non-Federal Dams. Locustville Pond Dam (RI 01408) Mass/RI Coastal Basin, Hopkinton, Rhode Island. Phase I Inspection Report.

    DTIC Science & Technology

    1981-01-01

    Ungated spillway capacity (right) at top of dam. 1,050 CFS b. Ungated spillway capacity (left) at top of dam. 450 CFS 4. Ungated spillway capa- city ...JUNE 14, 1945 INSPECTED ITS j. Vo KE ILY 0. PERRY SARLE DAN No. 26 ANAE LOCUSTVILLE DAM - 8uo -Tow ON CITY HOPKINTON On BRUSH BROOK PAWCATUOC WATERSIEO...SMITH DAN o. ..AND LOCAL RESIDX1T Tow 09 CITY HOPKINTON a. ~,, IOE PAWCATUOC WATEASNES OWNE MR.SISH C/C SAYSROOXE MiFG CO6 vps ET ANI .1 REPORT a. NEW

  12. National Program for Inspection of Non-Federal Dams. Berry Pond Dam (NH 00105), NHWRB 195.01, Merrimack River Basin, Pittsfield, New Hampshire. Phase I Inspection Report.

    DTIC Science & Technology

    1978-08-01

    report. It. KEY WORDS (Genemeo on e old@ #006 e ry*l neem , mid DifneUtt a1 blos fmmiS..) DAMS, -INSPECTION, DAM SAFETY, Merrimack River Basin...week, readiness exercises to . remove stop-logs should be conducted once per year, trees should be removed from the right abutment, and in the absence...several trees were standing at the right abutment area. Two seepage areas were noted on the downstream slope of the earth dam. One seepage point is located

  13. National Program for Inspection of Non-Federal Dams. Lower Eddy Pond Dam (VT 00230), Richelieu River Basin, Rutland, Vermont. Phase I Inspection Report.

    DTIC Science & Technology

    1981-03-01

    westerly side of the dam and the Vermont Depart- ment of Water Resources was notified. 4. The dam was inspected on December 6, 1980, by A. Peter Barranco ...entered by: 1. Landtech Recreation Association by Phil Dechert and Harold Berger, Esq. 2. Agency of Environmental Conservation by A. Peter Barranco ...Environmental Conservation by A. Peter Barranco and David Callum. 3. Department of Public Safety by Earl Osgood. 4. Kenneth Cota, downstream property owner. 5

  14. National Program for Inspection of Non-Federal Dams. Middle Pond Dam (CT 00283), Farmington River Basin, Plymouth, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-06-01

    volumes available for the dam breach flows . Upon failure of the dam the flood wave would enter a large swamp. The initial impact area is an apartment...resulted in leaning and buidging of the downstream stone masonry wall. Con- tinued flow over the right spillway could lead to further collapse ...partially blocked by GENERAL CONDITION OF CONCRETE debris . j RUST OR STAINING ON CONCRETE SPALL ING __________________ EROSION OR CAVITATION CRACKING

  15. National Dam Safety Program. Harman’s Farm Pond Dam (MO 30150), Mississippi - Kaskaskia - St. Louis Basin, St. Francois County, Missouri. Phase I Inspection Report.

    DTIC Science & Technology

    1980-05-01

    conditon of the dam with respect to safety, based upon available data and visual inspection, in order to determine if the dam poses hazards to human life...conducted by personnel of L. Robert Kimball and Associates on October 19, 1979. The inspection team consisted of a hydro- logist, structural/ soils ...controlling the 100 year storm. The earth embankment appeared to be in fair conditon . No ero- sion or seepage was noted at the time of inspection. A

  16. National Program for Inspection of Non-Federal Dams. Coachlace Pond Dam (MA 00106), Nashua River Basin, Clinton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1978-10-01

    engineering Judgment and practice, and is hereby submitted for approval. CHARLES G. TIERSCH, Chairman Chief, Foundation and Materials Branch 5 5 Engineering...embankment. Further- more, information on the type, shear strength, and permeability of the soil and/or rock materials of the dam embankment apparently does...Height _ _ _ - S Slopes& Upstre.am Face , / Downstre.am Face !4’.." / Width across top /f’ I o,’ 8. Classification of Dam by Materials Earth.* Conc

  17. Solar pond power plant feasibility study for Davis, California

    NASA Technical Reports Server (NTRS)

    Wu, Y. C.; Singer, M. J.; Marsh, H. E.; Harris, J.; Walton, A. L.

    1982-01-01

    The feasibility of constructing a solar pond power plant at Davis, California was studied. Site visits, weather data compilation, soil and water analyses, conceptual system design and analyses, a material and equipment market survey, conceptual site layout, and a preliminary cost estimate were studied. It was concluded that a solar pond power plant is technically feasible, but economically unattractive. The relatively small scale of the proposed plant and the high cost of importing salt resulted in a disproportionately high capital investment with respect to the annual energy production capacity of the plant. Cycle optimization and increased plant size would increase the economical attractiveness of the proposed concept.

  18. National Program for Inspection of Non-Federal Dams. Griswold Pond Dam(MA00292), Suagus River Basin, Suagus Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-10-01

    drainage area consists of 90 acres (0.14 square miles) directly tribu - tary to Griswold Pond plus an additional 51 acres (0.08 square miles) which...previous recoriandations thnat wvider spillways are needed, and that either’ the tops of’ the danis should be raised or the spilways lowered to obtain

  19. National Program for Inspection of Non-Federal Dams. Parks Pond Dam (CT 00071), Housatonic River Basin, Danbury, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1980-07-01

    vacinity and my guess is that the dam is founded on the material of the original stream bed which is probably gravel. The original spillway surface might... vacinity , vary from 360 c.f.s to over 1100 c.f.s.,’These figures are for the floods in the fall of 1955 which are the largest ever recorded in the New

  20. National Program for Inspection of Non-Federal Dams. Longwater Pond Dam (MA 00171), Taunton River Basin, Easton, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-04-01

    Town of Easton, Easton, Massachusetts 02334, and Mr. Oliver Ames, 295 Lee Street, Brookline, Massachusetts 02146 , joint I owners of the Dam. Copies...of Easton, Massachusetts (Telephone 617- 238-1091) and by Mr. Oliver Ames, 295 Lee Street, Brookline, Massachusetts 02146 (Tele- phone 617-482-5270

  1. Recent sediment studies refute Glen Canyon Dam hypothesis

    USGS Publications Warehouse

    Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

    2002-01-01

    Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

  2. Recent sediment studies refute Glen Canyon Dam Hypothesis

    NASA Astrophysics Data System (ADS)

    Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

    Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

  3. National Program for Inspection of Non-Federal Dams. Freeses Pond Dam (NH-00472), NHWRB-61.02, Piscataqua River Basin, Deerfield, Phase I Inspection Report.

    DTIC Science & Technology

    1979-05-01

    wingwall on its upstream face. The spillway is an uncontrolled, free - overfall structure with a vertical upstream face and slightly inclined downstream...the stop log controlled outlet and the free overfall spillway. During the inspection, the following observations of the hydraulic characteristics of...water surface is provided by the controlled outlet and the free overfall spillway. At the time of the visual inspection the pond level was about 0.1

  4. National Dam Safety Program. Silver Lake Dam (NJ00469), Wallkill River Basin, Tributary to Franklin Pond Creek, Sussex County, New Jersey. Phase I Inspection Report.

    DTIC Science & Technology

    1981-05-01

    It. NUMBER OF PAGES Trenton, NJ 08625 65 IT. MONITORING AGENCY NAME & AoORESS(r rerf ,,,,t ha C.n. llhiE OM.) IS. SECURITY CLASS. (of thi t. t) U.S...WOROS (Cantlam an m ,*-e ai i mem med identiy by Slac* Vdi) Dams National Dam Safety Program Embanknents Wallkill River Basin, NJ Visual Inspection Silver...0t 0ac 5 0.’e 0. 03*q.uf 4A AL- V) c I ’-S I- CC LUD LC 4Jl r 0 0 c 4.) 0 to) * D 0 0 W OC .0 (0.0 I- V; 41 Z-; (• Ŕ 0-" 0Ŕ >0.04- 030 4-’ 0 0 v 0 CC

  5. National Program for Inspection of Non-Federal Dams. Houghton Pond Dam (MA 00444), Charles River Basin, Holliston, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-07-01

    Engineers guidelines, the test flood for this dam is one-half the Probable Maximum Flood (1/2 PMF). Hydraulic analyses in- dicate that the test flood ...6.5 ft. in height in the main spillway, the total spillway capacity is approximately 280 cfs, which is 18 percent of the test flood outflow. The Town...are not intended to provide detailed hydrologic and hydraulic analyses. In accordance with the established Guidelines, the test flood is based on the

  6. National Program for Inspection of Non-Federal Dams. Leesville Pond Dam (MA 00141), Blackstone River Basin, Worcester, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1978-08-01

    ARMY ( I " E INEW ENGLAND DIVISION, CORPS OF ENGINEERS WALTHAM, MASS. 02154 A" d.,., t b AUGUST, 1978 i 8O".---A 4. 09 28 066 DISCLAIMER NOTICE THIS...Report. An alternative to these .- recommendations would be draining the reerpir an breaching or removing the dam.., Edward M. Greco, P.E. S IProject...Division APPROVAL RECOMMENDED: "JOE B . FRYAR Chief, Engineering Division PREFACE This report is prepared under guidance contained in Recommended

  7. National Dam Safety Program. Oldham Pond Dam (NJ00238), Passaic River Basin, Molly Ann Brook, Passaic County, New Jersey. Phase 1 Inspection Report

    DTIC Science & Technology

    1980-01-01

    Environm~ental Protection Jan Division of Water Resources ______________ Trenton, NJ 08625 122 14. ONIORIG AENCYNAM & DDRSS(f difernt romConrollng ffie...of the structure. (6) Investigate the reasons for the uneven surface of the crest, including the area where a hole has been filled with concrete and...design remedial measures as needed. (7) Design and implement necessary remedial measures to prevent erosion of the toe of the dam by water flowing in

  8. National Program for Inspection of Non-Federal Dams. Meetinghouse Pond Dam (MA 01018), Merrimack River Basin, Westminster, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1978-11-01

    rutted the crest of the dam. The channel portion of the spillway and the spillway walls have been covered with shotcrete as shown in Photo Nos. 10, 12...and 13. The shotcrete is becoming loose and local areas have spalled off, especially at the left wall. The weir flashboards are in good condition but...maintenance work and the spillway has some loose and spalled shotcrete . The spillway sidewalls are in fair condition. The shot- crete cover on the

  9. National Program for Inspection of Non-Federal Dams. Supply Pond Dam (NH 00123), NHWRB 165.06, Merrimack River Basin, Nashua, New Hampshire. Phase I Inspection Report.

    DTIC Science & Technology

    1979-02-01

    UNCLAIFEDF/ 1/1 N C0 • - • " " •- "*• 36 sm 2 wi " _25 hlhh"Z r 6? II, MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANOARDS-I963-A . I, I...classification, and in accordance with the Corps of Engineers guidelines, the Test Flood (TF) would be between the 100-year flood and one-half of the Prob- able...Maximum Flood (PMF). Since the hazard potential is on • the low side of the SIGNIFICANT category, the test flow into Supply Pond was taken as the 100

  10. National Program for Inspection of Non-Federal Dams. Browns Pond Dam MA 00192, North River Basin, Peabody, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1978-12-01

    Applicable Closure Not Applicable Access Not Applicable Regulating facilities Not Applicable Spillwa~ Type Broad - crested Length of weir , feet 6.0 Crest ...overflow weir is flanked by stone masonry training walls. Water discharged from the pond through the outlet Structure flows * underground for a distance of...Area 1-3 • b. Discharges at Damsite 1-4 . . c. Elevation 1-4 d. Reservoir 1-4 e. Storage 1-5 f. Reservoir Surface 1-5 .-. . - .. l - -° -,-- . Page No. g

  11. Estimating the ratio of pond size to irrigated soybean land in Mississippi: a case study

    Treesearch

    Ying Ouyang; G. Feng; J. Read; T. D. Leininger; J. N. Jenkins

    2016-01-01

    Although more on-farm storage ponds have been constructed in recent years to mitigate groundwater resources depletion in Mississippi, little effort has been devoted to estimating the ratio of on-farm water storage pond size to irrigated crop land based on pond metric and its hydrogeological conditions.  In this study, two simulation scenarios were chosen to...

  12. National Program for Inspection of Non-Federal Dams. Wheeler Pond Dam (CT 00239), Thames River Basin, Montville, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1978-09-01

    Type Overflow uncon- trolled 2. Length of Weir Total length 54.0 21.0 ogee type + 33.0 * ~ free overfall type -* ? 9 SW 1*@ ~W W W - W W@ W, W W, W, W...am has a maximum height of 20.0 ft. and is approx. 54.0 ft. long. Based u ’pon the visual inspection at the site, the lack of engineering back-up...Federal Dams. This report is presented for your use and is based upon a visual inspection, a review of the past perfor- mance and a brief hydrological

  13. National Program for Inspection of Non-Federal Dams. Highland Pond Dam (CT 00147), Connecticut River Basin, Middletown, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-04-01

    them. This follow- up action is vitally important. Copies of this report have been forwarded to the Department of Environ- mental Protection, and to the...dam there was one area of bulging, along with an area of seepage, and a number of voids up to 6 inches wide between stones. Based on its small size...about 30 feet up - stream from the crest of the spillway. The 2. 5 foot wide and 2 foot high outlet emerges at the bottom of the downstream face of

  14. National Dam Safety Program. Deer Park Pond Dam (NJ00502), Delaware River Basin, Tributary to Musconetcong River, Warren County, New Jersey. Phase I Inspection Report.

    DTIC Science & Technology

    1981-08-01

    of two 12-inch cast iron pipes 15 feet apart that run under this spillway. The dam has a hydraulic height of 16.4 feet and a crest width ranging from...Regulating Outlets Type - Two 12-inch pipes Length - 117 feet (estimated) Upstream inlets not seen, pipes are 15 feet center to center Access - each is...are badly rusted. (3) Low-Level Outlet. Two 12-inch cast iron pipes were observed at the toe of the spillway. However, no valves or inlet structure

  15. National Program for Inspection of Non-Federal Dams. Woods Pond (Valley Mill) Dam (MA 00731), Housatonic River Basin, Lee-Lenox, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-07-01

    Housatonic River 20. ABSTRACT (CMOSM 0m gmO 0#ds N mee v aIF WH I O I.oM 6 U" E) 1.MIM-) The damn ia rock-filled timber crib spillway structure 165 ft...should delineate the routine " .-. operational procedures and maintenance work to be done on the dam to ensure safe , satis-"- factory operation and to...Cnnditlon: 1. Safe - 2. Minor rcoairs needed X ______ 3. Conditltrnally safe - major repairs needed________ 4. Unsafq_________ 5. Rosorvoir impoundment

  16. National Program for Inspection of Non-Federal Dams. Potash Pond Dam (CT 00193), Thames River Basin, Windham, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1981-01-01

    UNCLASSIFIED F/G /13 NL IEEEEEEEE//BBBE!CBSI IIIIIEEE.: momo Wo 1 115 Ji L.1111., I= J~2 L6 ’ll- MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF... Michael Jacuch, Willimantic, Connecticut. Copies of this report will be made available to the public, upon request, by this office under the Freedom of...failure. 1-2 .’: e. Ownership. The dam is presently owned by Dr. Michael ?Jacuch, RFD #2, Willimantic, Connecticut. Phone (203) 527-3684. f. Operator

  17. National Program for Inspection of Non-Federal Dams. Baker Pond Dam VT 00135, Richelieu River Basin, Brookfield, Vermont. Phase I Inspection Report.

    DTIC Science & Technology

    1980-06-01

    toe of the dam. The entire area at the toe between the outlet pipe and the 900 bend was wet and soggy. In some locations water was emerging from beneath...plan by 11 feet deep. The upstream end is fitted with stoplogs the full depth of the structure. The outlet pipe is a 48 inch reinforced concrete pipe ...This seepage enters the outlet channel at a point about 20 feet downstream of the head wall of the outlet pipe . The flow at this point is shown in

  18. Development of a submersible shadowgraph for the study of interfaces in salt-gradient solar ponds

    SciTech Connect

    Huacuz, J.M.; Sierra, F.; Venegas, C.; Ramos, C. )

    1989-01-01

    In this paper the processes of development and testing of a submersible shadowgraph are described. This instrument was devised as a tool for the study of interfaces in salt-gradient solar ponds. Tests were carried out in the solar pond of the University of Texas at El Paso. Photographs of interfaces inside the pond were taken for the first time. The submersible shadowgraph can be stationed inside the pond for time dependent studies of a given region, or it can be used to scan the pond depth.

  19. Turbidity study of solar ponds utilizing seawater as salt source

    SciTech Connect

    Li, Nan; Sun, Wence; Shi, Yufeng; Yin, Fang; Zhang, Caihong

    2010-02-15

    A series of experiments were conducted to study the turbidity reduction in solar ponds utilizing seawater as salt source. The experiment on the turbidity reduction efficiency with chemicals indicates that alum (KAl(SO{sub 4}){sub 2}.12H{sub 2}O) has a better turbidity control property because of its strongly flocculating and also well depressing the growing of algae and bacteria in the seawater. In comparison with bittern and seawater, our experiment shows that the residual brine after desalination can keep limpidity for a long time even without any chemical in it. Experiments were also conducted on the diffusion of turbidity and salinity, which show that the turbidity did not diffuse upwards in the solution. In the experiment on subsidence of soil in the bittern and saline with the same salinity, it was found that soil subsided quite quickly in the pure saline water, but very slowly in the bittern. In this paper we also proposed an economical method to protect the solar pond from the damage of rain. Finally, thermal performance of a solar pond was simulated in the conditions of different turbidities using a thermal diffusion model. (author)

  20. National Program for Inspection of Non-Federal Dams. North Pond Dam (CT 00450), Housatonic River Basin, Goshen, Connecticut, North Pond Dikes (CT 00681), Housatonic River Basin, Norfolk, Connecticut. Phase I Inspection Program.

    DTIC Science & Technology

    1979-08-01

    office under the Freedom of Information Act . In the case of this report the release date will be thirty days from the date of this letter. I wish to take...OPERATIONAL PROCEDURES 4.1 REGULATING PROCEDURES North Pond acts as a storage reservoir for a distribution reservoir downstream and the single low level outlet...Springfield 157,000 158.0 994 19. Ball mountain 190,000 172.0 1,105 20. Townshend 228,000 106.0(278 total) 820 21. Surry Hountain 63,000 100.0 630 22. Otter

  1. Solar ponds

    NASA Astrophysics Data System (ADS)

    Tabor, H.

    1981-01-01

    The history and current status of salt-gradient non-convecting solar ponds are presented. These ponds are large-area collectors, capable of providing low-cost thermal, mechanical, or electrical energy using low-temperature turbo-generators. The basic theory of salt-gradient solar ponds is sketched; the effects of wind, leakage, and fouling and their constraints on location selection for solar ponds are discussed. The methods of building and filling the ponds, as well as extracting heat from them are explained in detail. Practical operating temperatures of 90 C can be obtained with collection efficiencies between 15% and 25%, demonstrating the practical use of the ponds for heating and cooling purposes, power production, and desalination. A condensed account of solar pond experience in several countries is given. This includes the 150 kW solar pond power station (SPPS) operating in Israel since December, 1979 and a 5000 kW unit currently under development. A study of the economics involved in using the ponds is presented: despite a low conversion efficiency, the SPPS is shown to have applications in many countries.

  2. Verifying Pressure of Water on Dams, a Case Study

    PubMed Central

    Bayrak, Temel

    2008-01-01

    Sensing and monitoring deformation pattern of dams is often one of the most effective ways to understand their safety status. The main objective of the present study is to find the extent to which rising reservoir level affects the mechanism of deformation of the Yamula dam under certain changes in the reservoir level conditions during the first filling period. A new dynamic deformation analysis technique was developed to analyze four geodetic monitoring records consisting of vertical and horizontal displacements of nine object points established on the dam and six reference points surrounding it, to see whether the rising reservoir level is responsible for the vertical and horizontal deformations during the first filling period. The largest displacements were determined in the middle points of the dam construction. There is an apparent linear relationship between the dam subsidence and the reservoir level. The dynamic deformation model was developed to model this situation. The model infers a causative relationship between the reservoir level and the dam deformations. The analysis of the results determines the degree of the correlation between the change in the reservoir level and the observed structural deformation of the dam. PMID:27873819

  3. National Dam Inspection Program. Silt Pond B, (NDI Number PA 00824 PENN DER Number 63-77) Ohio River Basin, Pigeon Creek, Washington County, Pennsylvania. United States Steel Corporation, Raw Materials Division. Phase I Inspection Report.

    DTIC Science & Technology

    1981-03-01

    Classification: Silt Pond B is classified as a "high" hazard dam. In the event of a dam failure , at least seven inhabited dwellings could be subjected to...emergency pro- cedure to alert or evacuate downstream residents upon threat of a dam failure . 4.5 EVALUATION The maintenance program should be continued...i 4-4 4-) 4-.) .1 -4 C3C -4 0OC 0L b3 L. >- LC o L 0) 4)-) 4. C -)Q)V 10 cO C 30 &.CV0 .- ) a 0.,I ) .0 L u C.-li CL .4L0 &.( tO a) 0 C) 0. mLcC 4z3

  4. Deformation Monitoring Studies and GPR Application on Dams

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2015-12-01

    Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Geometric changes at the dam surface and in the galleries are defined using geodetic methods. Physical and geometrical changes in embankment inside are defined using non-geodetic methods. This study provides information about the deformation monitoring techniques of the dams, dam safety and related analysis. The case study is the deformation monitoring of Atatürk Dam, 6th largest dam of world considering the reservoir volume, which was constructed on Euphrates (Fırat) River having importance for providing drinking water, hydroelectric power and irrigation. In the study, brief information is given about this dam and the methods of geodetic and non-geodetic deformation monitoring measurements applied by various disciplines. Bathymetric surveying techniques in the water covered area and Real Time Kinematic (RTK) GNSS surveying technique on the other area were used in order to determine the topography of the embankment and reservoir surfaces. Contour maps were drawn to determine the slumping and heaving areas. Also Ground

  5. Seismic performance of arch dams on non-homogeneous and discontinuous foundations (a case study: Karun 4 Dam)

    NASA Astrophysics Data System (ADS)

    Ferdousi, A.

    2017-06-01

    The present study set out to investigate the nonlinear seismic response of the dam-reservoir-rock foundation system, taking into consideration the effects of change in the material properties of discontinuous foundation. To this end, it is important to provide the proper modeling of truncated boundary conditions at the far-end of rock foundation and reservoir fluid domain and to correctly apply the in situ stresses for rock foundation. The nonlinear seismic response of an arch dam mainly depends on the opening and sliding of the dam body's contraction joints and foundation discontinuities, failure of the jointed rock and concrete materials, etc. In this paper, a time domain dynamic analysis of the 3D dam-reservoir-foundation interaction problem was performed by developing a nonlinear Finite Element program. The results of the analysis of Karun-4 Dam revealed the essential role of modeling discontinuities and boundary conditions of rock foundation under seismic excitation.

  6. Beaver Dam Effects on Gravel Transport Patterns - a Case Study

    NASA Astrophysics Data System (ADS)

    Bunte, K.; Swingle, K. W.; Potyondy, J. P.; Abt, S. R.

    2011-12-01

    Beaver dams are numerous in mountain streams, but little is known about gravel transport in those streams. The dams may be fully functioning and retain all incoming sediment or partially permeable to sediment or be almost completely removed. Beaver dams in their various states of preservation can have a profound influence on stream morphology and bedload transport. During the spring of 2011, the authors made a time series study of bedload transport in a mountain stream dominated by beavers dams. Dams occurred with a frequency of one every 50 feet and showed a range of decay and fluvial influence. Gravel transport was sampled with bedload traps over a 2-month long snowmelt highflow season. The reach-average gradient was 0.03 and stream widths ranged from 3 to 8 m. The stream bed was incised 0.5 to 1.5 m deep into a floodplain and typically trapezoidal in its cross-sectional shape. Much of the floodplain consisted of filled-in beaver dams. Partially breached dams that were permeable to gravel transport acted as an obstacle, forcing the flow around sharp bends. Complex hydraulic conditions developed in the vicinity of the bends with backwater eddies upstream and downstream of the remnant dam. Wake eddies at the downstream side of dam remnants caused gravel deposits. The tortuous channel course around the bends caused strong secondary currents that forced gravel transport into a narrow pathway along one of the banks causing a strong lateral concentration of transport. The pathway had a bed of fine and medium gravel, while the remainder of the bed consisted mostly of coarse gravel and cobbles that became immobile shortly after peak flows. Tracer experiments indicated that most of the mobile gravel traveled along that bankward path, even though flow velocities and depths were considerably smaller than in the stream center. Over the highflow season, flows increased to about 160% of the 1.5 year recurrence interval (Q1.5) within about a week and then remained within the

  7. A Theoretical Study of Cold Air Damming.

    NASA Astrophysics Data System (ADS)

    Xu, Qin

    1990-12-01

    The dynamics of cold air damming are examined analytically with a two-layer steady state model. The upper layer is a warm and saturated cross-mountain (easterly or southeasterly onshore) flow. The lower layer is a cold mountain-parallel (northerly) jet trapped on the windward (eastern) side of the mountain. The interface between the two layers represents a coastal front-a sloping inversion layer coupling the trapped cold dome with the warm onshore flow above through pressure continuity.An analytical expression is obtained for the inviscid upper-layer flow with hydrostatic and moist adiabatic approximations. Blackadar's PBL parameterization of eddy viscosity is used in the lower-layer equations. Solutions for the mountain-parallel jet and its associated secondary transverse circulation are obtained by expanding asymptotically upon a small parameter proportional to the square root of the inertial aspect ratio-the ratio between the mountain height and the radius of inertial oscillation. The geometric shape of the sloping interface is solved numerically from a differential-integral equation derived from the pressure continuity condition imposed at the interface.The observed flow structures and force balances of cold air damming events are produced qualitatively by the model. In the cold dome the mountain-parallel jet is controlled by the competition between the mountain-parallel pressure gradient and friction: the jet is stronger with smoother surfaces, higher mountains, and faster mountain-normal geostrophic winds. In the mountain-normal direction the vertically averaged force balance in the cold dome is nearly geostrophic and controls the geometric shape of the cold dome. The basic mountain-normal pressure gradient generated in the cold dome by the negative buoyancy distribution tends to flatten the sloping interface and expand the cold dome upstream against the mountain-normal pressure gradient (produced by the upper-layer onshore wind) and Coriolis force (induced

  8. Dam design can impede adaptive management of environmental flows: a case study from the Opuha Dam, New Zealand.

    PubMed

    Lessard, JoAnna; Hicks, D Murray; Snelder, Ton H; Arscott, David B; Larned, Scott T; Booker, Doug; Suren, Alastair M

    2013-02-01

    The Opuha Dam was designed for water storage, hydropower, and to augment summer low flows. Following its commissioning in 1999, algal blooms (dominated first by Phormidium and later Didymosphenia geminata) downstream of the dam were attributed to the reduced frequency and magnitude of high-flow events. In this study, we used a 20-year monitoring dataset to quantify changes associated with the dam. We also studied the effectiveness of flushing flows to remove periphyton from the river bed. Following the completion of the dam, daily maximum flows downstream have exceeded 100 m(3) s(-1) only three times; two of these floods exceeded the pre-dam mean annual flood of 203 m(3) s(-1) (compared to 19 times >100 m(3) s(-1) and 6 times >203 m(3) s(-1) in the 8 years of record before the dam). Other changes downstream included increases in water temperature, bed armoring, frequency of algal blooms, and changes to the aquatic invertebrate community. Seven experimental flushing flows resulted in limited periphyton reductions. Flood wave attenuation, bed armoring, and a shortage of surface sand and gravel, likely limited the effectiveness of these moderate floods. Floods similar to pre-dam levels may be effective for control of periphyton downstream; however, flushing flows of that magnitude are not possible with the existing dam infrastructure. These results highlight the need for dams to be planned and built with the capacity to provide the natural range of flows for adaptive management, particularly high flows.

  9. National Program for Inspection of Non-Federal Dams. Singletary Pond Dam (MA 00144), Blackstone River Basin, Millbury, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-02-01

    these guidelines may be obtained from the Office of Chief of Engineers, Washington, D.C. 20314. The purpose of a Phase I Investigation is to identify...were obtained in part from field surveys which were per- formed in conjunction with the Flood Insurance Study for the Town of Millbury. a. Drainage Area...All of the information for the Phase I Investigation had to be obtained from visual examination and limited measurements at the site. This information

  10. Preliminary study of solar ponds for salinity control in the Colorado River Basin. Technical report

    SciTech Connect

    Boegli, W.J.; Dahl, M.M.; Remmers, H.E.

    1982-12-01

    In this study, the Bureau of Reclamation investigates the technical and economic benefits of using solar salt-gradient ponds in the Colorado River Basin to provide salinity control and to produce project power and freshwater. It was assumed that the saline water needed for pond construction would be transported to one of two dry lakebeds in the Basin(Danby Dry Lake in southern California or Sevier Dry Lake in western Utah) as part of a salinity control/coal transport project. The ponds would be used to generate electric power that could be integrated with the Bureau's power grid or used in combination with thermal energy from the ponds to power commercially available desalination systems to produce freshwater. Economic benefits were compiled for two methods of concentrating the necessary brine for the ponds--one representing stage construction using collected brine only and the other using salt at the site to produce the concentrated brine.

  11. Study for reclamation of land occupied by solar evaporation pond at UCIL, Bhopal, India.

    PubMed

    George, K V; Patil, M R; Swaminathan, R

    2001-12-01

    Solar Evaporation Ponds (SEP) were used by Union Carbide India Limited (UCIL), Bhopal for storage of wastewater containing high concentrations of inorganic chemicals especially chlorides. Area occupied by the SEPs had to be recovered due to closure of the plant. A prerequisite to the reclamation of the SEP area is a study of adjoining soil and groundwater, which may be contaminated due to possible leakage in the pond. Surface soil, subsurface soil and groundwater samples were collected and analysed. The electrical conductivity method was employed inside the pond to test for leak in the geo-membrane liner. This was further confirmed by physically checking the liners. Based on the wet period, total rainfall and evaporation rate of the region, drying of remaining wastewater by spreading in dry ponds followed by pond dismantling was scheduled.

  12. Municipal wastewater treatment with pond-constructed wetland system: a case study.

    PubMed

    Wang, X; Bai, X; Qiu, J; Wang, B

    2005-01-01

    The performance of a pond-constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond-constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.

  13. National Program for Inspection of Non-Federal Dams. Congamond Lakes Outlet (Middle Pond) (MA 00071), Connecticut River Basin, Southwick, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1979-03-01

    dam iscomprised of two earth embankments’CftAacnrlwi8fotid concrete box culvert with concrete...level was approximately three inches above the stop log sill. @ S b. Dam J.7 The dam consists of an earth embankment which acts as a highway fill leading...8217 ..-,. .. -**---.. .-. ,- ,~, , %, ." .-- ",, ....... *i*~~~~~~~ % --- ..... a~ aa -2- * Dam No. 2-7-279-5 Classification of Dan by Material: Embankments Bridge Earth Conc.

  14. Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996

    SciTech Connect

    Wilde, E.W.; Johnson, M.A.; Cody, W.C.

    1996-12-31

    This report describes the results of phytoplankton analyses from Par Pond samples collected between February 1995 and September 1996. The principal objective of the study was to determine the effect of refilling of Par Pond following repair of the dam on the phytoplankton community. Algal blooms are often responsible for fish kills and other detrimental effects in ponds and lakes, and it was postulated that decaying vegetation from formerly exposed sediments might trigger algal blooms that could result in fish kills in Par Pond following the refill. Sporadic algal blooms involving blue-green algae were detected, especially during the summer of 1996. However, the data derived from the study demonstrates that overall, the refilling effort caused no significant negative impact to the pond attributable to phytoplankton dynamics.

  15. Dam located to east of powerhouse, view from south. This ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Dam located to east of powerhouse, view from south. This dam holds back the waters of the Chattahoochee River to form the mill pond north of Riverdale Cotton Mill - Riverdale Cotton Mill, Powerhouse & Dam, Valley, Chambers County, AL

  16. 8. VIEW OF DAM 83, SHOWING OLD SOURIS RIVER CHANNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF DAM 83, SHOWING OLD SOURIS RIVER CHANNEL FROM THE DOWNSTREAM FACE OF THE DAM WITH POND A IN THE BACKGROUND, LOOKING SOUTH - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  17. Rapid surface-water volume estimations in beaver ponds

    NASA Astrophysics Data System (ADS)

    Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

    2017-02-01

    Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

  18. A comparative study of the growth of Tetraselmis sp. in large scale fixed depth and decreasing depth raceway ponds.

    PubMed

    Das, Probir; Thaher, Mahmoud Ibrahim; Hakim, Mohammed Abdul Quadir Mohd Abdul; Al-Jabri, Hareb Mohammed S J; Alghasal, Ghamza Saed H S

    2016-09-01

    In this study, an alternative approach was proposed where excess seawater would be added only during inoculation (DD) rather than daily addition (FD). Growth and metabolite contents of Tetraselmis sp. weren't affected for daily increase of 2% NaCl salinity. Tetraselmis sp. was then cultured in DD and FD pond. In DD pond, initial culture depth was 23.5cm and its depth reduced as no water was added; for FD pond, everyday sterilized seawater was added to maintain 20cm depth. DD pond had higher biomass productivity compared to FD pond, until DD pond was deeper than FD pond; metabolite content and FAME profile of Tetraselmis sp. were also similar in both cultures. Therefore, considering the simplicity in operation, halo tolerant microalgae can be grown in DD pond method. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Thermal storage case study: Combined building mass and cooling pond

    SciTech Connect

    Arnold, D.

    2000-07-01

    In 1994 a large U.K. credit card company decided to relocate and centralize its offices and operations from a number of city center sites to the outskirts on a green field site. The company decided that the concept for the new building should be environmentally friendly, i.e., naturally ventilated and cooled by openable windows. However, during initial studies there was concern over whether natural cooling and ventilation alone would be adequate to maintain thermal comfort during hot weather. The design solution was to provide a mix of passive and mechanical systems that could be switched in response to internal conditions and the prevailing weather. The object was to use passive features, i.e., the building thermal mass and storage and cooling effects of a pond, to maintain thermal comfort whenever possible and only switch to mechanical cooling under extreme conditions. The building was occupied progressively during the spring of 1997. The case study covers the period from the initial design concept to the end of the first 18 months of occupation.

  20. Valuating Ecosystem Services of Urban Ponds - case study from Bangladesh

    NASA Astrophysics Data System (ADS)

    Carle, Nina

    2016-04-01

    A climate risk assessment for the city of Barisal was carried out by a consultancy firm, financed by KfW Development Bank of Germany. Due to high dependencies on natural capital of people in developing countries they are facing high vulnerability when it comes to changes of the asset category 'natural capital' (here: urban ponds), whether due to the exposition on climate (change) related impacts, implemented measures or land use change. With a closer view on the city's assets, the question remained open to the author 1) Under current conditions, what is the demand for ecosystem services (ES) 2) What is the value of the benefits and the how much is the contribution to the city's welfare? 3) What are the future changes in the demand for ES? And what are the future changes on the supply side (pressures and threats to the ecosystem)? Methodology: The City of Barisal in Bangladesh has a calculated number of around 10.000 urban rain-fed ponds,representing 6.5% of the city area, which represents a huge natural water supply and gives the city its characteristic face. In August 2015 a user survey was conducted in the city of Barisal, in every ward (administrative unit), to determine the demand for ecosystem services related to urban ponds, evaluating over 600 ponds. The findings will present the huge variation of provisioning ecosystem services and an important regulating service, related to economic and domestic use, in a spatial resolution. It will be shown, how the importance of ES changes, by changing the unit of analysis (families or ponds or the city) and the importance for the livelihood of pond owners and users. A relationship between pond area(m2) and number of users was detected, also the role of compensation payments for the pond owners by the users. It will be shown how natural capital, privately and publicly owned,contributes in an important way in buffering unequal distribution of societies resources in the short- and long-run. However society's demand for ES

  1. Why Does Amphibian Chytrid (Batrachochytrium dendrobatidis) Not Occur Everywhere? An Exploratory Study in Missouri Ponds

    PubMed Central

    Strauss, Alex; Smith, Kevin G.

    2013-01-01

    The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened resident amphibian larvae (Rana (Lithobates) sp.) for Bd infection, and characterized the aquatic physiochemical environment of each pond (temperature pH, conductivity, nitrogen, phosphorus, and chlorophyll-a). Our goal was to generate hypotheses toward answering the question, “Why does Bd not occur in all apparently suitable habitats?” Bd occurred in assayed amphibians in 11 of the 29 ponds in our study area (38% of ponds). We found no significant relationship between any single biotic or abiotic variable and presence of Bd. However, multivariate analyses (nonmetric multidimensional scaling and permutational tests of dispersion) revealed that ponds in which Bd occurred were a restricted subset of all ponds in terms of amphibian community structure, macroinvertebrate community structure, and pond physiochemistry. In other words, Bd ponds from 6 different conservation areas were more similar to each other than would be expected based on chance. The results of a structural equation model suggest that patterns in the occurrence of Bd among ponds are primarily attributable to variation in macroinvertebrate community structure. When combined with recent results showing that Bd can infect invertebrates as well as amphibians, we suggest that additional research should focus on the role played by non-amphibian biota in determining the presence, prevalence, and pathogenicity of Bd in amphibian populations. PMID:24086681

  2. National Program for Inspection of Non-Federal Dams. Storrs Pond Dam (NH 00050), NHWRB Number 108.07, Connecticut River Basin, Hanover, New Hampshire. Phase I Inspection Report.

    DTIC Science & Technology

    1979-11-01

    revealed that deterioration of the concrete surface of the spillway and the invert of the spillway discharge tunnel . It is small in size with a hazard...the center of the dam. The discharge tunnel exits on the downstream toe of the dam, an has overall dimensions of - 10 feet ,by 10 feet, with the...revealed deterioration of the concrete surface of the spillway and the invert of the spillway 4.... discharge tunnel , rotted stumps on the dam, brush and wet

  3. Nonlinear Seismic Analysis of Morrow Point Dam: A Study for the United States Bureau of Reclamation

    SciTech Connect

    Noble, C R; Solberg, J

    2004-02-20

    This research and development project was sponsored by the United States Bureau of Reclamation (USBR), who are best known for the dams, power plants, and canals it constructed in the 17 western states. The mission statement of the USBR's Dam Safety Office, located in Denver, Colorado, is ''to ensure Reclamation dams do not present unacceptable risk to people, property, and the environment.'' The Dam Safety Office does this by quickly identifying the dams which pose an increased threat to the public, and quickly completing the related analyses in order to make decisions that will safeguard the public and associated resources. The research study described in this report constitutes one element of USBR's research and development work to advance their computational and analysis capabilities for studying the response of dams to strong earthquake motions. This project focused on the seismic response of Morrow Point Dam, which is located 263 km southwest of Denver, Colorado.

  4. 216-U-10 Pond and 216-Z-19 Ditch characterization studies

    SciTech Connect

    Last, G.V.; Duncan, D.W.; Graham, M.J.; Hall, M.D.; Hall, V.W.; Landeen, D.S.; Leitz, J.G.; Mitchell, R.M.

    1994-02-01

    The chemical, reprocessing of spent nuclear fuels at the US Department of Energy`s Hanford Site has generated large volumes of radioactive liquid effluents. The majority of these effluents have been used strictly for cooling or other supportive functions and have been discharged to ditches and ponds. The 216-U-10 Pond and 216-Z-19 Ditch are two such disposal facilities. These facilities are components of an integrated system of ditches, ponds, and overflow facilities collectively referred to as the U-Pond disposal system. The U-Pond system has been used since 1943 and has received a large variety of radioisotopes from several sources. This study covered tho major aspects of the environment, including wind resuspension, biological uptake and transport, geologic distribution in surface and subsurface sediments, and ground-water impacts. The long-term use of U-Pond and the Z-19 Ditch has resulted in the localized accumulation of transuranic and fission product inventories as a result of sorption and filtration of particulates onto the uppermost sediments.

  5. Davis Pond freshwater prediversion biomonitoring study: freshwater fisheries and eagles

    USGS Publications Warehouse

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  6. National Dam Inspection Program. Ross Pond Dam (NDI I.D. PA-0265, DER I. D. 058-142), Susquehanna River Basin, Tributary of Drinker Creek, Susquehanna County, Pennsylvania. Phase I Inspection Report

    DTIC Science & Technology

    1981-08-01

    visual examination of the spillway and the visible portions of the outlet works. 3. The evaluation of the downstream area hazard potential. The specific ... areas , at about the midheight of the dam, signs of sloughing were observed. Sloughing appeared to be surficial, caused by surface runoff. In these...of 0.98 square mile and impounds a reservoir with a surface area of 51.4 acres at normal pool level. The flood discharge facility of the dam

  7. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    USGS Publications Warehouse

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  8. Evaluation of the effect of porous check dam location on fine sediment retention (a case study).

    PubMed

    Hassanli, A M; Nameghi, A Esmaeli; Beecham, S

    2009-05-01

    This study was carried out to evaluate the influence of porous check dam location on the retention of fine sediments in the Droodzan watershed in Southern Iran. Five long streams with several porous check dams that were more than 27 years old were studied. In each stream three check dams: at the very upstream section, at the middle section and at the far downstream section were selected for analysis. A number of samples from trapped sediments and from the undisturbed soils in the stream banks (adjacent to the check dams) were collected. Laboratory analysis showed that the soil samples taken from undisturbed banks have smaller particle sizes compared to the trapped sediments. The results indicated that the check dams located at the far downstream sections were more efficient at trapping fine sediment than those located at the middle sections. Also the check dams located at the middle sections were more effective than those located at the upstream sections. Comparison of sediment texture also showed that the portion of clay and silt trapped by the check dams decreased from the downstream sections toward the upstream sections. Hence, whenever, the retention of fine sediments is the primary function of the check dams, it appears that they should be located in the far downstream sections of a stream. The experimental analysis indicated that using broken and angular rocks instead of rounded rocks in porous check dam's construction improves the effectiveness of the check dams for the retention of fine sediments. The analysis of the failed check dams also showed that erosion of the bank sides underneath the check dams is the primary cause of dam collapse.

  9. Floods from tailings dam failures.

    PubMed

    Rico, M; Benito, G; Díez-Herrero, A

    2008-06-15

    This paper compiles the available information on historic tailings dam failures with the purpose to establish simple correlations between tailings ponds geometric parameters (e.g., dam height, tailings volume) and the hydraulic characteristics of floods resulting from released tailings. Following the collapse of a mining waste dam, only a part of tailings and polluted water stored at the dam is released, and this outflow volume is difficult to estimate prior the incident. In this study, tailings' volume stored at the time of failure was shown to have a good correlation (r2=0.86) with the tailings outflow volume, and the volume of spilled tailings was correlated with its run-out distance (r2=0.57). An envelope curve was drawn encompassing the majority of data points indicating the potential maximum downstream distance affected by a tailings' spill. The application of the described regression equations for prediction purposes needs to be treated with caution and with support of on-site measurement and observations. However, they may provide a universal baseline approximation on tailing outflow characteristics (even if detailed dam information is unavailable), which is of a great importance for risk analysis purposes.

  10. Application of CFD modelling to study the hydrodynamics of various anaerobic pond configurations.

    PubMed

    Vega, G P; Peña, M R; Ramírez, C; Mara, D D

    2003-01-01

    The simulation of hydrodynamics and transport phenomena in waste stabilization ponds is a developing tool worth studying in order to understand their internal processes and interactions. Pond design involves several physical, hydrological, geometric and dynamic variables so as to provide high hydrodynamic efficiency and maximum substrate utilization rates. CFD modelling allows the combination of these factors to predict the behaviour of ponds having different configurations. The two-dimensional depth-integrated model MIKE 21 was used in this study to simulate hydrodynamic and advection-dispersion processes in a full-scale anaerobic pond (AP) located in southwest Colombia. A set of 12 configurations including sludge contents, inlet-outlet positioning, baffling and pond geometry were modelled. Results showed that a crosswise (diagonally opposite) inlet-outlet layout, a length-to-breadth ratio of 2:1, plus provision of two cross baffles at 1/3 L and 2/3 L were the most effective measures to improve overall AP hydrodynamics and dispersion patterns.

  11. Outdoor experimental ponds (mesocosms) designed for long-term ecotoxicological studies in aquatic environment.

    PubMed

    Caquet, T; Lagadic, L; Jonot, O; Baturo, W; Kilanda, M; Simon, P; Le Bras, S; Echaubard, M; Ramade, F

    1996-07-01

    Outdoor artificial ponds (mesocosms) of 12 m3 were designed for long-term ecotoxicological studies. Sediment, macrophytes (Typha angustifolia and Elodea canadensis), and free and caged freshwater snails [Lymnaea palustris (Müller)] and wood lice (Asellus aquaticus L.) were collected in nearby natural ecosystems and introduced in the mesocosms. Sixty goldfish (Carassius auratus L.) were caged in each pond. Introduced species developed and reproduced in every mesocosm. Animal species (mainly insects and amphibians) spontaneously colonized the ponds, developed, and reproduced. The resulting communities qualitatively resemble those living in natural lentic systems in the surrounding area. Homogenity in physical and chemical conditions and in abundance of phytoplanktonic, periphytic, and macroinvertebrate communities between the different mesocosms was assessed during the stabilization period (8 months). Except for periphyton biomass, no divergent evolution was observed between the ponds. Mesocosm water was slightly eutrophic, alkaline (mean pH: 8.47 +/- 0.09), and moderately hard and mineralized. The homogenous and realistic environmental conditions and high ecological representativity of the outdoor experimental ponds were suitable for extensive ecotoxicological studies. Considerations on the choice and origin of introduced species and on possible interactive effects of the transfer of organisms from natural environments, maintainance conditions, and pollutant exposure are discussed.

  12. Proceedings of Dam Safety Training Program

    SciTech Connect

    Tanner, D.T.; Sloan, R.C.; Tockstein, C.D.; Price, J.T.; Stone, S.D.; Newton, D.; Spearman, E.L.; Hodge, R.D.; Jenkins, C.; Chapman, L.D.

    1985-01-01

    The papers included are titled: Assessment of Instrumentation Data, Design of Concrete Dams, Instrumentation of Dams, TVA's Dam Safety Program, Design of Earth Dams, Hydrologic Design of Dams, Emergency Action Plans, TVA Dam Safety Studies and Project Rehabilitation, Collection of Instrumentation Data, Structural Inspection at Non-Power Dams, Construction of Dams, and Site Selection and Geology.

  13. Holocene beaver damming, fluvial geomorphology, and climate in Yellowstone National Park, Wyoming

    NASA Astrophysics Data System (ADS)

    Persico, Lyman; Meyer, Grant

    2009-05-01

    We use beaver-pond deposits and geomorphic characteristics of small streams to assess long-term effects of beavers and climate change on Holocene fluvial activity in northern Yellowstone National Park. Although beaver damming has been considered a viable mechanism for major aggradation of mountain stream valleys, this has not been previously tested with stratigraphic and geochronologic data. Thirty-nine radiocarbon ages on beaver-pond deposits fall primarily within the last 4000 yr, but gaps in dated beaver occupation from ~ 2200-1800 and 950-750 cal yr BP correspond with severe droughts that likely caused low to ephemeral discharges in smaller streams, as in modern severe drought. Maximum channel gradient for reaches with Holocene beaver-pond deposits decreases with increasing basin area, implying that stream power limits beaver damming and pond sediment preservation. In northern Yellowstone, the patchy distribution and cumulative thickness of mostly < 2 m of beaver-pond deposits indicate that net aggradation forced by beaver damming is small, but beaver-enhanced aggradation in some glacial scour depressions is greater. Although 20th-century beaver loss and dam abandonment caused significant local channel incision, most downcutting along alluvial reaches of the study streams is unrelated to beaver dam abandonment or predates historic beaver extirpation.

  14. Baseline studies in the Elwha River ecosystem prior to dam removal: Introduction to the special issue

    USGS Publications Warehouse

    Duda, Jeffrey J.; Freilich, Jerry; Schreiner, Edward G.

    2008-01-01

    The planned removal of two dams that have been in place for over 95 years on the Elwha River provides a unique opportunity to study dam removal effects. Among the largest dams ever considered for removal, this project is compelling because 83% of the watershed lies undisturbed in Olympic National Park. Eighteen million cubic meters of sediment have accumulated in and will be released from the reservoirs, and there is potential for rehabilitating depressed Pacific salmon runs. Researchers from academia, non-profit organizations, federal and state governments, and the Lower Elwha Klallam Tribe are currently assessing baseline ecological conditions of the Elwha River as part of dam removal studies. We introduce dam removal topics, provide a brief history of the dams, and summarize the ecology of the Elwha River basin as an introduction to a special issue devoted to research in the watershed.

  15. Experimental Study on Impact Load on a Dam Due to Debris Flow

    Treesearch

    lwao Miyoshi

    1991-01-01

    When a dam is struck by mud or debris flow, it is put under a great impact load and sometimes is destroyed. To prevent such destruction, it is important to perform basic research about the impact load on a dam due to debris flow. Thus, we have made an experimental study and tried to establish a method to estimate such a impact load on the dam. The experiment was...

  16. Assessment of microcystin concentration in carp and catfish: a case study from Lakshmikund pond, Varanasi, India.

    PubMed

    Singh, Shweta; Asthana, Ravi Kumar

    2014-06-01

    The present study was conducted to analyse microcystin concentrations in Lakshmikund pond, Varanasi, India, as well as in carp and catfish of the pond. The concentrations of microcystin were found well above the WHO guidelines (1 µg/L) both for the dissolved and particulate fractions of bloom samples. The microcystin concentrations in different organs of carp and catfish were in the following sequence; liver > gut > kidney > gall bladder > gills > muscles and gut > liver > kidney > gall bladder > gills > muscles, respectively. The bioaccumulation of microcystin in carp and catfish was negatively correlated with body weight, and showed species specificity. The higher bioaccumulation of microcystin in muscles of catfish (>tenfold) over carp indicates a possible threat to human beings on consumption of catfish. Therefore, to avoid animal and human intoxication, routine analyses of microcystin in pond water as well as fishes are strongly recommended.

  17. Interaction of Dams and Landslides--Case Studies and Mitigation

    USGS Publications Warehouse

    Schuster, Robert L.

    2006-01-01

    In the first half of the 20th century, engineering geology and geotechnical engineering were in their infancy, and dams were often built where landslides provided valley constrictions, often without expert site investigation. Only the most important projects were subjected to careful geologic examination. Thus, dams were often built without complete understanding of the possible geotechnical problems occurring in foundations or abutments. Most of these dams still exist, although many have undergone costly repairs because of stability or leakage problems. Today, however, every effort is made in the selection of damsites, including those sited on landslides, to provide foundations and abutments that are generally impervious and capable of withstanding the stresses imposed by the proposed dam and reservoir, and possible landslides. By means of a literature search, technical interviews, and field inventory, I have located 254 large (at least 10 m high) dams worldwide that directly interact with landslides; that is, they have been built on pre-existing landslides or have been subjected to landslide activity during or after construction. A table (Appendix table A) summarizes dam characteristics, landslide conditions, and remedial measures at each of the dams. Of the 254 dams, 164 are earthfill, 23 are rockfill, and 18 are earthfill-rockfill; these are flexible dam types that generally perform better on the possibly unstable foundations provided by landslides than do more rigid concrete dams. Any pre-existing landslides that might impinge on the foundation or abutments of a dam should be carefully investigated. If a landslide is recognized in a dam foundation or abutment, the landslide deposits commonly are avoided in siting the dam or are removed during stripping of the dam foundation and abutment contacts. Contrarily, it has often been found to be technically feasible and economically desirable to site and construct dams on known landslides or on the remnants of these

  18. Biodiversity of algae and protozoa in a natural waste stabilization pond: a field study.

    PubMed

    Tharavathi, N C; Hosetti, B B

    2003-04-01

    A field study was carried out on the biodiversity of protozoa and algae from a natural waste stabilization pond during November, 1996 to April, 1997. The raw waste and pond samples were analysed for physico-chemical and biological parameters. High dissolved oxygen (DO) coinciding with phytoplankton peak was recorded. The algae--Chlorella vulgaris, Scenedesmus acuminatus, Oscillatoria brevis and Nostoc piscinale and Protozoa--Paramecium caudatum, Acanthamoeba sp., Bodo saltans and Oikomonas termo were obvious as dominant species, whereas algae Ochromonas pyriformis and Synura uvella and protozoa, Didinium masutum and Stentor coerulus were noted as rare species. Totally 71 species of algae and 13 species of protozoa were identified.

  19. National Program for Inspection of Non-Federal Dams. Milton Three Ponds Dam, (NH 00320), State Number 161.06, Piscataqua River Basin, Milton, New Hampshire. Phase I Inspection Report.

    DTIC Science & Technology

    1978-08-01

    recommendations described in Section 7 and ask . ..- --. t h a t y o u k e e p m e i n f o rm e d o f t h e a c t i o n s t a k e n t o im p l e m e n t t h e m...acquired the dam and water rights in December of 1963. f. Operator. Mr. Vernon K . Knowlton, Chief Engineer, . S New Hampshire Water Resources Board, 37...which comprises the top section of the dam olav , was built in 1968. 0 14 0 0 S S S 0 S - . . . . . . . . . . . . . .. . . e. SeismicStability . This

  20. Salton Sea Solar Pond Power Plant Design Study and Regional Applicability

    NASA Technical Reports Server (NTRS)

    French, R. L.

    1984-01-01

    Ormat collected and organized the data base and conducted conceptual plant design, performance, and cost analysis. JPL conducted site-specific studies related to solar pond chemistry, soil biological activity, and dike design and construction. WESTEC conducted environmental investigation studies and performed an environmental assessment. SCE provided planning support for licensing and permitting and technical evaluations of the system design and cost estimate.

  1. Salton Sea Solar Pond Power Plant Design Study and Regional Applicability

    NASA Technical Reports Server (NTRS)

    French, R. L.

    1984-01-01

    Ormat collected and organized the data base and conducted conceptual plant design, performance, and cost analysis. JPL conducted site-specific studies related to solar pond chemistry, soil biological activity, and dike design and construction. WESTEC conducted environmental investigation studies and performed an environmental assessment. SCE provided planning support for licensing and permitting and technical evaluations of the system design and cost estimate.

  2. Dam Removal Information Portal (DRIP)—A map-based resource linking scientific studies and associated geospatial information about dam removals

    USGS Publications Warehouse

    Duda, Jeffrey J.; Wieferich, Daniel J.; Bristol, R. Sky; Bellmore, J. Ryan; Hutchison, Vivian B.; Vittum, Katherine M.; Craig, Laura; Warrick, Jonathan A.

    2016-08-18

    The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history of river management, science is just beginning to guide our understanding of the physical and ecological implications of dam removal. Ultimately, the “lessons learned” from previous scientific studies on the outcomes dam removal could inform future scientific understanding of ecosystem outcomes, as well as aid in decision-making by stakeholders. We created a database visualization tool, the Dam Removal Information Portal (DRIP), to display map-based, interactive information about the scientific studies associated with dam removals. Serving both as a bibliographic source as well as a link to other existing databases like the National Hydrography Dataset, the derived National Dam Removal Science Database serves as the foundation for a Web-based application that synthesizes the existing scientific studies associated with dam removals. Thus, using the DRIP application, users can explore information about completed dam removal projects (for example, their location, height, and date removed), as well as discover sources and details of associated of scientific studies. As such, DRIP is intended to be a dynamic collection of scientific information related to dams that have been removed in the United States and elsewhere. This report describes the architecture and concepts of this “metaknowledge” database and the DRIP visualization tool.

  3. Environmentally safe design of tailing dams for the management of iron ore tailings in Indian context.

    PubMed

    Ghose, Mrinal K; Sen, P K

    2005-10-01

    The need for the disposal of iron ore tailings in an enviornmentally firiendly manner is of great concern. This paper investigates the soil engineering properties for the construction of iron ore tailing dam, its foundation, construction materials and design data used for the construction analysis of the tailing dam. Geophysical investigations were carried out to establish the bedrock below the spillway. A computer programme taking into account the Swedish Slip Circle Method of analysis was used in the stability analysis of dam. It also focuses on the charactierstics of the tailings reponsible for the determination of optimum size of tailing pond for the containment of the tailings. The studies on the settling characteristics of tailings indicate much less area in comparison to the area provided in the existing tailing ponds in India. In the proposed scheme, it is suggested to provide an additional unit of sedimentation tank before the disposal of tailings to the tailing pond.

  4. Groundwater-Surface Water Interaction: A Case Study of Embankment Dam Safety Assessment in Sweden.

    NASA Astrophysics Data System (ADS)

    Ferdos, F.; Dargahi, B.

    2015-12-01

    Seepage, when excessive and unimpeded, can cause embankment dam failure. Such failures are often initiated by internal erosion and piping. Modelling these phenomena in embankment dams, accounting for the groundwater-surface water interactions, is crucial when performing dam safety assessments. The aim of this study was to evaluate the applicability of modelling seepage flows in multi-region dams using a finite element based multi-physics model. The model was applied to the Trängslet dam, the largest dam in Sweden. The objectives were to analyze the characteristics of both the flow and the surface-ground water interactions occurring in the dam, including: i) the saturated and unsaturated laminar flow regimes within the dam body, ii) the non-linear through-flow in the dam shoulders' coarse material, iii) the influence of the surface waves in the reservoir on the seepage flow by coupling the physics to a hydrodynamic interface, and iv) the influence of a conceptual "erosion tunnel" on the seepage flow and its interaction with the surface water flow by coupling the physics to a CFD interface. The focus of the study was on the influence of the transient water head boundary condition, surface waves and the internal erosion tunnel on the location of the phreatic line and the seepage flow rate. The simulated seepage flow of the dam in its original condition tallied with the monitoring measurements (40-70 l/s). The main feature found was the relatively high position of the phreatic line, which could compromise the stability of the dam. The combination of the seepage model with the reservoir hydrodynamics indicated a negligible influence of the surface waves on seepage flow. Results from the combination of the seepage model with fluid dynamics indicated that a conceptual "erosion tunnel" placed within the dam, even as high as in the unsaturated zone, significantly affects the phreatic line's position. This also causes the seepage flow to increase by several orders of

  5. Brief reconnaissance study for the addition of hydropower for Mayodan Dam, Mayodan, North Carolina

    SciTech Connect

    Gebhard, Jr., T. G.

    1982-09-09

    The feasibility of retrofitting the Mayodan Dam near Mayodan, North Carolina for power generation was examined. This dam, which has a developable head of 20 ft., was built in 1920 for impounding a small run-of-the-river water reservoir. The study of environmental, institutional, safety and economic factors showed that hydroelectric power development at this site appears to be economically feasible. (LCL)

  6. Solar ponds

    SciTech Connect

    Jayadev, T.S.; Edesess, M.

    1980-04-01

    This report first describes the different types of solar ponds including the nonconvecting salt gradient pond and various saltless pond designs. It then discusses the availability and cost of salts for salt gradient ponds, and compares the economics of salty and saltless ponds as a function of salt cost. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirements is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future.

  7. Freshwater ponds

    USDA-ARS?s Scientific Manuscript database

    This book chapter summarizes aquaculture pond ecology. The underlying theme is how ponds supply essential life-support functions (food, oxygen, and waste treatment) and how those functions are subsidized by external resources as culture intensity increases. Ponds are confined bodies of standing wate...

  8. Par Pond vegetation status 1996

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned.

  9. Carbon sequestration function of check-dams: a case study of the Loess plateau in China.

    PubMed

    Wang, Yafeng; Chen, Liding; Gao, Yang; Wang, Shuai; Lü, Yihe; Fu, Bojie

    2014-11-01

    Check-dams are the most common structures for controlling soil erosion in the Loess Plateau. However, the effect of check-dams on carbon sequestration, along with sediment transport and deposition, has not been assessed over large areas. In this study, we evaluated the carbon sequestration function of check-dams in the Loess Plateau. The results indicate that there were approximately 11 000 check-dams distributed in the Loess Plateau, with an estimate of the amount of sediment of 21 × 10⁹ m³ and a soil organic carbon storage amount of 0.945 Pg. Our study reveals that check-dams in the Loess Plateau not only conserve soil and water but also sequester carbon.

  10. National Dam Safety Program. Duck Creek - State Wildlife Refuge - Pond 1 (MO 40063), Lower Mississippi - St. Francis Basin, Bollinger and Stoddard Counties, Missouri. Phase I Inspection Report.

    DTIC Science & Technology

    1980-03-01

    feet. The effective opening of each gate is 6 feet wide by 5 feet deep. The water level is controlled by two Hardesty steel gates (72" x 60"). The...out of Pond 1 through the sluice gate to Ditch 1. (b) Type - 2 - 7Z inch x 60 inch Hardesty steel gates (c) Opening (each) - 6 feet x 5 feet (d) Inlet...level is controlled by two Hardesty steel gates (72" x 60"). The top of roadway across the intake structure was at an elevation of 349.73 N.G.V.D

  11. Visibility from Roads Predict the Distribution of Invasive Fishes in Agricultural Ponds

    PubMed Central

    Kizuka, Toshikazu; Akasaka, Munemitsu; Kadoya, Taku; Takamura, Noriko

    2014-01-01

    Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that

  12. Visibility from roads predict the distribution of invasive fishes in agricultural ponds.

    PubMed

    Kizuka, Toshikazu; Akasaka, Munemitsu; Kadoya, Taku; Takamura, Noriko

    2014-01-01

    Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that

  13. Sedimentation and sediment chemistry, Neopit Mill Pond, Menominee Indian Reservation, Wisconsin, 2001

    USGS Publications Warehouse

    Fitzpatrick, Faith A.; Peppler, Marie C.

    2003-01-01

    The volume, texture, and chemistry of sediment deposited in a mill pond on the West Branch of the Wolf River at Neopit, Wis., Menominee Reservation, were studied in 2001-2002. The study was accomplished by examining General Land Office Survey Notes from 1854, establishing 12 transects through the mill pond, conducting soundings of the soft and hard bottom along each transect, and collecting core samples for preliminary screening of potential contaminants. Combined information from transects, cores, and General Land Office Survey notes were used to reconstruct the pre-dam location of the West Branch of the Wolf River through the mill pond. Neopit Mill Pond contains approximately 253 acre-ft of organic-rich muck, on average about 1.2 ft thick, that was deposited after the dam was built. Elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with creosote and pentachlorophenol were found in post-dam sediment samples collected from Neopit Mill Pond. Trace-element concentrations were at or near background concentrations. Further study and sampling are needed to identify the spatial extent and variability of the PAHs, pentachlorophenol, and other byproducts from wood preservatives

  14. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China.

    PubMed

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-12-02

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the "source-pathway-target" in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method.

  15. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    PubMed Central

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-01-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  16. Recent dynamics of thermokarst ponds in discontinuous permafrost: a paleolimnological study from subarctic Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Bouchard, F.; Francus, P.; Pienitz, R.

    2011-12-01

    Accelerated thawing and erosion of permafrost is leading to the release of organic carbon through greenhouse gas emissions, especially in thermokarst (thaw) ponds and lakes. These aquatic ecosystems are widespread throughout arctic and subarctic regions; however their natural variability and temporal evolution recorded in the bottom sediments are poorly understood. Here we present a multi-proxy study conducted in a subarctic site with many thermokarst ponds near Kuujjuarapik-Whapmagoostui, on the eastern shore of Hudson Bay, at the southern edge of the discontinuous and scattered permafrost zone. Sedimentological, geochemical and biological (diatoms) analyses have been performed on short sediment cores (10-20 cm) retrieved from limnologically contrasted ponds. Long-term (14C) and short-term (210Pb, 137Cs) chronologies were also established. Analyses revealed two distinct sedimentary facies, from bottom to top: 1) massive marine silts and clays deposited during postglacial Tyrrell Sea transgression (ca. 8000 to 6000 cal yr BP), subsequently emerged by glacio-isostatic rebound and more recently (ca. 1500 to 400 cal yr BP) affected by permafrost inception and growth; 2) laminated organic-rich lacustrine muds deposited since permafrost thawing and subsidence, i.e. since thermokarst pond inception (the last centuries). Almost absent from the bottom sediments (lower facies), benthic and planktonic diatoms appeared highly abundant in surface lacustrine sediments (upper facies) and reflected past changes in bottom water properties (e.g., pH, dissolved organic carbon, water color). Despite displaying strikingly different water colors, the study ponds showed similar long-term developmental patterns regarding their biogeochemical properties (as recorded in the sediments), such as: decreasing mineral grain size (from silts to clays); decreasing major chemical element concentrations; increasing organic matter content and decreasing pH (establishment of peatland vegetation

  17. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  18. Analysis of Level of Analysis: Data Design, Sampling, and Treatment for Dam Removal Studies

    NASA Astrophysics Data System (ADS)

    Tullos, D.; Kibler, K.

    2008-12-01

    Dam removal is increasingly implemented as a river restoration technique and yet substantial uncertainty exists regarding the short and long-term outcomes of this practice. While dam removal is largely considered a restorative action, many questions remain, including those regarding the effects of sediment release to downstream aquatic ecosystems. How will sediment evacuation influence downstream channel morphology and associated ecology? Over what temporal and spatial scales will the sediment signal persist? Unpredictability of dam removal timing and insufficient funding for monitoring has lead to inadequate rigor in study designs, which presents a substantial hurdle to resolving these questions with confidence. To begin addressing questions of impact magnitude and extent, we present an example that focuses on detecting physically and biologically significant changes in grain size distributions associated with downstream migration of reservoir sediments. In presenting a set of experimental methods and an analytical toolkit that may be applied to a variety of dam removal scenarios, we suggest utilization of exploratory baseline data and pre-emptive analyses of statistical power to provide guidance in prioritizing research hypotheses, craft monitoring strategies, and select appropriate analytical methods. Recognizing that constraints inherent to many dam removal studies will limit the experimental design choices that may be implemented, and thus the objectives that may be realized, the outcome is a branching of two strategies (descriptive and systematic) for monitoring and reporting results of dam removals. Data from the Brownsville, Chiloquin, and Savage Rapids dam removals in Oregon are used to demonstrate sampling design principles and analytical strategies.

  19. Critical study of current situation of Vrănicioara tailing pond on Cavnicului Valley, risks and consequences

    NASA Astrophysics Data System (ADS)

    Bud, I.; Duma, S.; Gusat, D.; Pasca, I.; Bud, A.

    2017-05-01

    In northern Romania, there are numerous tailing ponds, resulting from mining activities that present significant environmental risks. Some of them, including Vrănicioara tailing pond, were the subject of technical projects for ecological rehabilitation. Vrănicioara pond is located on the right side of Cavnic Valley, downstream Cavnic town, about 4 kilometers far. It has about 500 m length and is located parallel to the road linking Baia Sprie and Cavnic localities. Chemical and physical stability of the tailing pond before rehabilitation interest the research, analysis and conclusions were published in several scientific meetings. In addition, close to the pond at less than 100 m, an open pit has developed, exploiting andesite by mining blast, increasing the risk of physical stability by continuous exposure to vibration. This activity currently continues, advancing towards the tailing pond body. The critical study addresses the current state of Vrănicioara Tailing Pond, analysis of some rehabilitation works done incorrectly, analysis of chemical stability that was not a priority during rehabilitation. Research intention is heading to water analysis confirming the existence of acid drainage that was not stopped or at least reduced. The scientific approach is based on the Technical Standards for Waste Deposits, in force in Romania, providing the rules to ensure physical and chemical stability.

  20. Study of the saltwater pond at Capoterra, southern Sardinia: General characteristics

    NASA Astrophysics Data System (ADS)

    de Martis, B.; de Miranda Restivo, M. A.; Mocci Demartis, A.; Serra, E.

    1992-05-01

    Capoterra Pond in southern Sardinia is described and analyzed with respect to its morphological, meteorological, physical and chemical characteristics, and its zoobenthic, zooplankton, and phytoplankton biocenoses. The birdlife, flora, and riparian associations of vegetation are studied in order to draw international attention to the importance of this lagoon, the precariousness of its ecosystem, the seriousness of current attempts to destabilize it, and the need to encourage the Sardinian authorities to initiate conservation measures, especially as rare birds have found their niches there.

  1. Aerial radiological surveys of Steed Pond, Savannah River Site: Dates of surveys, 1984--1989

    SciTech Connect

    Fritzsche, A.E.; Jobst, J.E.

    1993-09-01

    From June 1984 to August 1985, three aerial radiological surveys were conducted over Steed Pond at the Savannah River Site in South Carolina. In addition, Steed Pond was included in larger-area surveys of the Savannah River Site in subsequent years. The surveys were conducted by the Remote Sensing Laboratory of EG&G Energy Measurements, Inc., Las Vegas, Nevada, for the US Department of Energy. Airborne measurements were obtained for both natural and man-made gamma radiation over Steed Pond and surrounding areas. The first survey was conducted when the pond was filled to normal capacity for the time of the year. On September 1, 1984, the Steed Pond dam spillway failed causing the pond to drain. The four subsequent surveys were conducted with the pond drained. The second survey and the third were conducted to study silt deposits exposed by the drop in water level after the spillway`s opening. Steed Pond data from the February 1987 and April 1989 Savannah River Site surveys have been included to bring this study up to date.

  2. Dam safety: Morris Sheppard Dam rehabilitation

    SciTech Connect

    Garland, J.D.; Waters, R.H.; Focht, J.A. Jr.

    1995-12-31

    Morris Sheppard Dam is one of the world`s largest flat slab buttress dams. It is located on the Brazos River about 96 km (60 miles) west of Dallas - Fort Worth. Designed by Ambursen Dam Company, the dam was constructed between 1938 and 1941 at a cost of $8.7 million. In 1987, a maximum buttress movement of 114 mm (4.5 inches) was discovered. The dam was successfully rehabilitated between 1987 and 1994 at a cost of $36 million. This paper will describe: (1) the dam`s construction and operational history, (2) the lowering of the reservoir by 3.94 m (13 feet) as an emergency response when the movement was discovered, (3) the initial stabilization of the dam by the addition of relief wells and grouting, (4) the final stabilization using ballast to increase the weight of the dam, (5) the use of actual dam performance as a full-scale, long-term, load test to back-calculate realistic strength parameters, (6) the multiple sets of design stability criteria used to analyze the structure, and (7) the use of model studies to enlarge the dam`s stilling basin and design an emergency spillway to handle the PMF.

  3. Dover Dam Physical Model Study, Tuscarawas River, Dover OH

    DTIC Science & Technology

    2009-09-01

    noted. Figure 2. Dover Dam Model The accepted equations of hydraulic similitude , based on Froudian rela- tions, were used to express mathematical ... similitude . All dimensions and results in this report are presented in prototype scale, with all elevations referenced to (MSL) unless otherwise

  4. National Dam Inspection Program. Hathaway Pond Dam (NDI ID Number PA 00050, PennDER Number 58-06), Susquehanna River Basin, West Branch of Lackawanna River, Susquehanna County, Pennsylvania. Phase I Inspection Report

    DTIC Science & Technology

    1981-06-01

    34 ’" ’ , :J.. SECTION 3 - VISUAL INSPECTION 3.1 FINDINGS a. General - The dam was found to be in poor overall condition at the time of inspection on...outlet to basin divide. L = Length of water course from outlet to point opposite the centroid of drainage area. ca 1P MIC. AEI. BAKER, JR., INC. Subject...Pr.0 5V1A~ps- -s-zey -] V7 (/f.a 4 27. 4 tP.4,/)-7.4 o)) V= -z- 3 ~-/ A𔄃ZF f’- tje � 5V? 17,tt 7W,9 LV V10,xI: 0.30 -. . 7-,e r 4 7 ’i gesw’./7’ LV

  5. Retinal emboli and cardiovascular disease: the Beaver Dam Eye Study.

    PubMed Central

    Klein, Ronald; Klein, Barbara E K; Moss, Scot E; Meuer, Stacy M

    2003-01-01

    PURPOSE: To describe the 10-year incidence of retinal emboli, the associated risk factors, and the relationship of retinal emboli to stroke and ischemic heart disease mortality. METHODS: The Beaver Dam Eye Study (n = 4,926) is a population-based study of persons 43 to 86 years of age. Retinal emboli were detected at baseline (1988-1990) and at a 5-year (1993-1995) and a 10-year (1998-2000) follow-up by grading of stereoscopic 30 degrees color fundus photographs using standardized protocols. Cause-specific mortality was determined from death certificates. RESULTS: The 10-year cumulative incidence of retinal emboli was 1.5%. While adjusting for age and sex, the incidence of retinal emboli was associated with increased pulse pressure (odds ratio [OR] 4th versus 1st quartile range, 2.42; 95% confidence interval (CI), 0.98-5.97; P test of trend = .03), higher serum total cholesterol (OR, 2.77; 95% CI, 1.06-7.23; P = .03), higher leukocyte count (OR, 2.28; 95% CI, 1.04-4.96; P = .05), smoking status (OR current versus never smoker, 4.60: 95% CI, 2.08-10.16; P < .001), and a history of coronary artery bypass surgery (OR, 7.17; 95% CI, 3.18-16.18; P < .001) at baseline. While controlling for age, sex, and systemic factors, a significantly higher hazard of dying with a mention of stroke on the death certificate was found in people with retinal emboli (hazard ratio, 2.40; 95% CI, 1.16-4.99) compared with those without. CONCLUSIONS: The data show an association of smoking and cardiovascular disease with the incidence of retinal emboli. Also, persons with retinal emboli are at increased risk of stroke-related death. PMID:14971575

  6. Agricultural ponds support amphibian populations

    USGS Publications Warehouse

    Knutson, M.G.; Richardson, W.B.; Reineke, D.M.; Gray, B.R.; Parmelee, J.R.; Weick, S.E.

    2004-01-01

    In some agricultural regions, natural wetlands are scarce, and constructed agricultural ponds may represent important alternative breeding habitats for amphibians. Properly managed, these agricultural ponds may effectively increase the total amount of breeding habitat and help to sustain populations. We studied small, constructed agricultural ponds in southeastern Minnesota to assess their value as amphibian breeding sites. Our study examined habitat factors associated with amphibian reproduction at two spatial scales: the pond and the landscape surrounding the pond. We found that small agricultural ponds in southeastern Minnesota provided breeding habitat for at least 10 species of amphibians. Species richness and multispecies reproductive success were more closely associated with characteristics of the pond (water quality, vegetation, and predators) compared with characteristics of the surrounding landscape, but individual species were associated with both pond and landscape variables. Ponds surrounded by row crops had similar species richness and reproductive success compared with natural wetlands and ponds surrounded by nongrazed pasture. Ponds used for watering livestock had elevated concentrations of phosphorus, higher turbidity, and a trend toward reduced amphibian reproductive success. Species richness was highest in small ponds, ponds with lower total nitrogen concentrations, tiger salamanders (Ambystoma tigrinum) present, and lacking fish. Multispecies reproductive success was best in ponds with lower total nitrogen concentrations, less emergent vegetation, and lacking fish. Habitat factors associated with higher reproductive success varied among individual species. We conclude that small, constructed farm ponds, properly managed, may help sustain amphibian populations in landscapes where natural wetland habitat is rare. We recommend management actions such as limiting livestock access to the pond to improve water quality, reducing nitrogen input, and

  7. Baseline study of methane emission from anaerobic ponds of palm oil mill effluent treatment.

    PubMed

    Yacob, Shahrakbah; Ali Hassan, Mohd; Shirai, Yoshihito; Wakisaka, Minato; Subash, Sunderaj

    2006-07-31

    The world currently obtains its energy from the fossil fuels such as oil, natural gas and coal. However, the international crisis in the Middle East, rapid depletion of fossil fuel reserves as well as climate change have driven the world towards renewable energy sources which are abundant, untapped and environmentally friendly. Malaysia has abundant biomass resources generated from the agricultural industry particularly the large commodity, palm oil. This paper will focus on palm oil mill effluent (POME) as the source of renewable energy from the generation of methane and establish the current methane emission from the anaerobic treatment facility. The emission was measured from two anaerobic ponds in Felda Serting Palm Oil Mill for 52 weeks. The results showed that the methane content was between 35.0% and 70.0% and biogas flow rate ranged between 0.5 and 2.4 L/min/m(2). Total methane emission per anaerobic pond was 1043.1 kg/day. The total methane emission calculated from the two equations derived from relationships between methane emission and total carbon removal and POME discharged were comparable with field measurement. This study also revealed that anaerobic pond system is more efficient than open digesting tank system for POME treatment. Two main factors affecting the methane emission were mill activities and oil palm seasonal cropping.

  8. A Comparison of Three Rubber Dam Systems In Vivo--A Preliminary Study.

    PubMed

    Kapitán, Martin; Suchánková Kleplová, Tereza; Suchánek, Jakub

    2015-01-01

    The aim of this study was to compare the isolation systems OptraDam® Plus and OptiDam™ with the conventional rubber dam in terms of objective and subjective parameters. The isolation systems were applied during the dental treatment of the patients. The time of preparation, placement, presence and removal were measured and the quality of isolation was evaluated. The median time of rubber dam placement was 76 s (Q1=62 s; Q3=111.25 s). The application time of OptraDam® Plus was significantly longer compared to the other systems (P ® plus. The results presented in this study could guide clinicians for choosing the most appropriate isolation system.

  9. Marib Dam: the importance of environmental and health impact studies for development projects.

    PubMed

    Basahi, I A

    2000-01-01

    Marib Dam was built without an environmental impact assessment study which created many conflicts. In 1995 and 1996 its impact on water quality, agriculture and groundwater recharge and socioeconomics was studied. Lake water could suffer severe eutrophication when floods are weak and algae growth is not controlled. Introducing Tilapia nilotica provided biological control of algae growth. The dam positively affected agriculture and groundwater within the designed irrigation scheme but negatively affected them beyond it. The dam also negatively affected health conditions and increased conflicts over water distribution. It positively affected women by allowing them to work in agriculture and participate in decision-making. The dam raised income levels of farmers and encouraged tourism.

  10. A comparative hydrobiological study of a few ponds of Barak Valley, Assam and their role as sustainable water resources.

    PubMed

    Bhuiyan, J R; Gupta, S

    2007-10-01

    A hydrobiological study conducted in nine different ponds of a rural area of Barak Valley, Assam, showed that the concentrations of chemical parameters like dissolved oxygen, free carbon dioxide, pH, conductivity alkalinity nitrate, phosphate, calcium, magnesium, copper and zinc are within the permissible levels of drinking water quality standard of WHO and ISI. However iron content was higher in most of the ponds. A clear indirect relationship between iron concentration and euglenoids has been observed. Major phytoplankton taxa present in the ponds are Chlorophyceae, Cyanophyceae, Bacillariophyceae and Euglenophyceae. The study reveals that rural ponds can be a very good source of water for drinking, domestic use and fishery and should be conserved at any cost.

  11. The Dalles Dam, Columbia River: Spillway Improvement CFD Study

    SciTech Connect

    Cook, Chris B.; Richmond, Marshall C.; Serkowski, John A.

    2006-06-01

    This report documents development of computational fluid dynamics (CFD) models that were applied to The Dalles spillway for the US Army Corps of Engineers, Portland District. The models have been successfully validated against physical models and prototype data, and are suitable to support biological research and operations management. The CFD models have been proven to provide reliable information in the turbulent high-velocity flow field downstream of the spillway face that is typically difficult to monitor in the prototype. In addition, CFD data provides hydraulic information throughout the solution domain that can be easily extracted from archived simulations for later use if necessary. This project is part of an ongoing program at the Portland District to improve spillway survival conditions for juvenile salmon at The Dalles. Biological data collected at The Dalles spillway have shown that for the original spillway configuration juvenile salmon passage survival is lower than desired. Therefore, the Portland District is seeking to identify operational and/or structural changes that might be implemented to improve fish passage survival. Pacific Northwest National Laboratory (PNNL) went through a sequence of steps to develop a CFD model of The Dalles spillway and tailrace. The first step was to identify a preferred CFD modeling package. In the case of The Dalles spillway, Flow-3D was as selected because of its ability to simulate the turbulent free-surface flows that occur downstream of each spilling bay. The second step in development of The Dalles CFD model was to assemble bathymetric datasets and structural drawings sufficient to describe the dam (powerhouse, non-overflow dam, spillway, fish ladder entrances, etc.) and tailrace. These datasets are documented in this report as are various 3-D graphical representations of The Dalles spillway and tailrace. The performance of the CFD model was then validated for several cases as the third step. The validated model

  12. Brief reconnaissance study for the addition of hydropower for Spray Dam, Eden, North Carolina

    SciTech Connect

    Gebhard, T.G. Jr.

    1981-01-30

    The feasibility of retrofitting the Spray Dam near Eden, North Carolina for power generation was examined. This dam has a developable head of 10 ft., was built in 1898 for hydroelectric power generation with one of 2 installed units currently operating. The study of environmental, institutional, safety and economic factors showed that hydroelectric power development at this site is possible and that the economics of retrofits will depend on whether existing equipment can be repaired or will have to be replaced. (LCL)

  13. Brief reconnaissance study for the addition of hydropower for Craig Lake Dam, Asheville, North Carolina

    SciTech Connect

    Gebhard, T.G. Jr.

    1982-02-08

    The feasibility of retrofitting the Craig Lake Dam near Asheville, NC for power generation was examined. This dam has a developable head of 22 ft., was built in 1924 for water impoundment, but no water is currently impounded. The study of environmental, institutional, safety and economic factors showed that hydroelectric power development at this site is feasible if developed by a public agency which can borrow development cost money at municipal bond interest rates. (LCL)

  14. Brief reconnaissance study for the addition of hydropower for Carr Fork Dam, Sassafras, Kentucky

    SciTech Connect

    Gebhard, T.G. Jr.

    1982-05-24

    The feasibility of retrofitting the Carr Fork Dam near Hazard, KY for power generation was examined. This dam has a developable head of 80 ft and was built in 1975 to provide flood protection. The study of environmental, institutional, safety, and economic factors showed that the total investment cost would be $909,600 and that hydroelectric power development at this site is not feasible unless a higher price could be obtained for the power sold. (LCL)

  15. Estimating the ratio of pond size to irrigated soybeans land in Mississippi: A case study

    USDA-ARS?s Scientific Manuscript database

    Although more on-farm storage ponds have been constructed in recent years to mitigate groundwater resources depletion in Mississippi, little effort has been devoted to estimating the ratio of pond size to irrigated crop land based on pond matric and its hydrological conditions. Knowledge of this ra...

  16. DAM Safety and Deformation Monitoring in Dams

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.; Potts, L.; Miiama, J.; Mahgoub, M.; Rahman, S.

    2013-12-01

    Water is the life and necessity to water is increasing day by day with respect to the World population, rising of living standards and destruction of nature. Thus, the importance of water and water structures have been increasing gradually. Dams are among the most important engineering structures used for water supplies, flood controls, agricultural purposes as well as drinking and hydroelectric power. There are about 150.000 large size dams in the World. Especially after the Second World War, higher and larger capacity dams have been constructed. Dams create certain risks like the other manmade structures. No one knows precisely how many dam failures have occurred in the World, whereas hundreds of dam failures have occurred throughout the U.S. history. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some information, safety and the techniques about the deformation monitoring of the

  17. Surface Sediments in Precooler Ponds 2, 4, and 5: March 2000

    SciTech Connect

    Dunn, D.L.

    2001-01-29

    Pond 2, Pond 4, and Pond 5 are inactive reactor cooling impoundments built in 1961 on the R-Reactor Effluent System in the east-central portion of the Department of Energy's Savannah River Site in Aiken, South Carolina. These precooler ponds are part of the Par Pond cooling water system and are considered part of the Par Pond operable unit. The intent was not to characterize the ponds, but to identify the maximum levels of contamination that could be exposed if the ponds are drained to remove the danger of dam failure.

  18. Exploring Pond Water

    ERIC Educational Resources Information Center

    Raun, Chester E.; Metz, William C.

    1975-01-01

    An activity utilizing a bucket of pond water for study of microorganisms as presented to elementary school preservice and inservice teachers, and subsequently to their pupils, is described. Procedures for collecting, studying, tabulating data and extended activities are presented. (EB)

  19. Determinants of Retinal Venular Diameter: the Beaver Dam Eye Study

    PubMed Central

    Myers, Chelsea E.; Klein, Ronald; Knudtson, Michael D.; Lee, Kristine E.; Gangnon, Ronald; Wong, Tien Y.; Klein, Barbara E. K.

    2012-01-01

    Objective To describe how retinal venular diameter changes over time for an individual and to examine differences in these changes among people with different risk profiles. Design Population-based cohort study. Participants 4600 persons aged 43–86 years from the Beaver Dam Eye Study who participated in at least 1 examination and had venular diameter measured in the right eye. Methods Data from 4 examinations over 15 years were analyzed. Retinal venular diameter was measured from photographs at each examination by computer-assisted methods and summarized as the central retinal venular equivalent (CRVE). Associations of risk factors to concurrent CRVE measurements and changes in CRVE over time were determined using multivariate analyses. Main Outcome Measure CRVE. Results CRVE tended to narrow with age. Mean CRVE was about 5 µm smaller (225 vs. 230 µm) for the average 70-year-old compared to the average 50-year-old, and was about 13 µm smaller (217 vs. 230 µm) for the average 85-year-old compared to the average 50-year-old. Male sex (beta estimate [β]=5.34; 95% confidence interval [CI] 3.58, 6.90), current smoking (β=9.38; 95% CI 8.26, 10.49), and higher white blood cell count (per 1000/µL: β=0.95; 95% CI 0.74, 1.16) were independently associated with larger concurrent CRVE while higher mean arterial blood pressure (per 5 mmHg: β=−0.36; 95% CI −0.50, −0.23) and higher high-density lipoprotein cholesterol (per 10 mg/dL: β=−0.89; 95% CI −1.15, −0.63) were independently associated with smaller concurrent CRVE. History of cardiovascular disease (β=−0.16; 95% CI −0.26, −0.06) and presence of chronic kidney disease (β=−0.20; 95% CI −0.34, −0.05) were associated with a greater decrease in CRVE over time. Conclusions These data show that retinal venular diameter tended to narrow with age, and that concurrent venular diameter is independently associated with sex, blood pressure, high-density lipoprotein cholesterol, white blood cell

  20. Insights into the Effects of the Spatial Configuration of Flood Retention Ponds on Flood Frequency

    NASA Astrophysics Data System (ADS)

    Ayalew, T. B.; Krajewski, W. F.; Mantilla, R.

    2014-12-01

    As the construction of large dams for flood control purposes becomes no longer attractive due to their high cost and adverse environmental impacts, the use of spatially distributed flood retention ponds in both urban and rural settings is becoming an alternative flood management practice. However, little is known about how the spatial configuration of ponds and their storage and release capacities relative to their location in the drainage network affect the flood frequency at different locations in the catchment. In this study, we investigate this issue using a continuous simulation approach where a randomly generated rainfall time series is used to derive a hydrologic model that mimics the translation, aggregation, and attenuation of flows along the drainage network. We began by investigating how flood retention ponds that are configured either in series or in parallel affect the flood frequency using a hypothetical catchment (A=30 km2) whose drainage network is idealized using the deterministic Mandelbrot-Viseck tree. Our results show that ponds that are configured in parallel and placed at the upstream section of the basin offer a better peak flood reduction than ponds that are either configured in series along the main stem of the drainage network or a single bigger pond that is located at the outlet. The results also show that, for ponds that are configured in series, emptying the upstream dam first offers better regulation of flood peaks than emptying the downstream pond first. Moreover, our results show that, when the two ponds that are configured in series have different storage capacities, it is better to put the larger pond in the upstream section of the catchment. We further expanded the analysis to the Soap Creek catchment (A=660 km2) located in southeastern Iowa, and simulated a system of 132 flood retention ponds that have already been built across that catchment. Our results show how these ponds modify the flood frequency at different locations in

  1. National Dam Inspection Program. Stanford Avenue Stormwater Retention Pond (NDI Number PA-01146, DER Number 6-467), Delaware River Basin, Tributary to Wyomissing Creek, Berks County, Pennsylvania. Phase I Inspection Report

    DTIC Science & Technology

    1981-07-01

    refusal and six borings were drilled 10 feet into rock. Laboratory testinq included phvsical properties and compaction tests. Borrow materials from...be given to installing a trash rack at the low level outlet in the event that the fence should fail during a large storm oermitting large debris to...DAM STABILITY SEEPAGE STUDIES MATERIALS INVESTIGATIONS BORING RECORDS LABORATORY Complete records are located in FIELD the Township Engineer’s files

  2. Synthesis of Juvenile Salmonid Passage Studies at The Dalles Dam, Volume II, 2001-05

    SciTech Connect

    Johnson, Gary E.; Beeman, John W.; Duran, Ian; Puls, Andrew

    2007-08-15

    The overall goal of juvenile salmonid research at The Dalles Dam is to provide data to inform decisions on strategies to improve smolt survival rates at the project. Survival improvement strategies address the three primary passage routes at The Dalles Dam -- spillway, sluiceway, and turbines – with the general intent to increase spill and sluice passage and decrease turbine passage. Since the review by Ploskey et al. (2001a) of research during 1982-2000 at The Dalles Dam, the Corps funded over $20M of research in at least 39 studies during 2001-2006. The purpose of the current review is to synthesize juvenile salmonid passage data at The Dalles Dam (TDA) collected from 2001 through 2006. The data we synthesize comes from numerous research techniques employed to address particular study objectives at The Dalles Dam. The suite of techniques includes acoustic and radio telemetry, acoustic cameras, acoustic Doppler current profilers, balloon tags, computational fluid dynamics models, drogues, fixed and mobile hydroacoustics, fyke nets, physical scale models, PIT-tags, sensor fish, sonar trackers, and underwater video. Hydraulic data involves flow patterns and water velocities. Biological data involve forebay approach paths and residence times, horizontal and diel distributions, passage efficiencies and effectiveness, fish behaviors, tailrace egress and predation rates, and route-specific and total project survival rates. Data for 2001-2006 are synthesized in this report to provide, in conjunction with Ploskey et al. (2001a), resources for engineers, biologists, and dam operators to use when making decisions about fish protection measures for juvenile salmonids at The Dalles Dam. This review covers the major fish passage research efforts during 2001-2006 and includes sections on the Environmental Setting, Forebay and Project Passage Studies, Spill Studies, Sluiceway Studies, Turbine Studies, Smolt Survival Studies, and a Discussion.

  3. Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

    NASA Astrophysics Data System (ADS)

    Reynolds, Z. A.

    2015-12-01

    Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how

  4. Comprehensive Cooling Water Study: Volume 7, Ecology of Par Pond, Savannah River Plant: Final report

    SciTech Connect

    Wilde, E.W.

    1987-10-01

    The Comprehensive Cooling Water Study (CCWS) was initiated in 1983 to evaluate the environmental effects of the intake and release of cooling water on the structure and function of aquatic ecosystems at the Savannah River Plant. The initial report (Gladden et al., 1985) described the results from the first year of the study. This document is the final report and concludes the program. The report comprises eight volumes. The first is a summary of environmental effects. The other seven volumes address water quality, radionuclide and heavy metal transport, wetlands, aquatic ecology, Federally endangered species, ecology of Par Pond, and waterfowl. 222 refs., 31 figs., 67 tabs.

  5. Colonial Era Impoundment of the Northeastern United States: Beaver Trapping and Low- head Dam Construction

    NASA Astrophysics Data System (ADS)

    Salant, N.; Bain, D.; Brandt, S.

    2008-12-01

    Hydrologic systems of the northeastern United States were transformed by European settler activities. The colonial economy shifted engineered water structures from beaver dams to human dams built for power generation. While the geomorphic effects of human-constructed dams have recently garnered considerable attention, few studies have investigated how intensive trapping for the fur trade, the near extermination of the Northeast beaver population, and the consequent loss of beaver ponds altered the regional water balance. Although reconstructions of colonial beaver populations have been made, none link the decline in beavers to its hydrologic impact. Beaver population models based on pre-colonial population estimates, historic harvest rates, and current-day population dynamics were used to simulate the corresponding decrease in pond numbers over time. Beaver populations declined dramatically during the seventeenth century, with harvest rates estimated at 2,000-10,000 beavers per year, resulting in expatriation in some sub-regions by the early 1700s. Using contemporary estimates of beaver pond volumes, the calculated loss in pond storage between 1600 and 1840 was approximately 17 million cubic meters of water and sediment, considerably larger than estimated storage gains from dam construction in the same period, suggesting that beaver eradication was a major driver of hydrologic change during the colonial era.

  6. Investigation on trophic state index by artificial neural networks (case study: Dez Dam of Iran)

    NASA Astrophysics Data System (ADS)

    Saghi, H.; Karimi, L.; Javid, A. H.

    2015-06-01

    Dam construction and surface runoff control is one of the most common approaches for water-needs supply of human societies. However, the increasing development of social activities and hence the subsequent increase in environmental pollutants leads to deterioration of water quality in dam reservoirs and eutrophication process could be intensified. So, the water quality of reservoirs is now one of the key factors in operation and water quality management of reservoirs. Hence, maintaining the quality of the stored water and identification and examination of changes along time has been a constant concern of humans that involves the water authorities. Traditionally, empirical trophic state indices of dam reservoirs often defined based on changes in concentration of effective factors (nutrients) and its consequences (increase in chlorophyll a), have been used as an efficient tool in the definition of dam reservoirs quality. In recent years, modeling techniques such as artificial neural networks have enhanced the prediction capability and the accuracy of these studies. In this study, artificial neural networks have been applied to analyze eutrophication process in the Dez Dam reservoir in Iran. In this paper, feed forward neural network with one input layer, one hidden layer and one output layer was applied using MATLAB neural network toolbox for trophic state index (TSI) analysis in the Dez Dam reservoir. The input data of this network are effective parameters in the eutrophication: nitrogen cycle parameters and phosphorous cycle parameters and parameters that will be changed by eutrophication: Chl a, SD, DO and the output data is TSI. Based on the results from estimation of modified Carlson trophic state index, Dez Dam reservoir is considered to be eutrophic in the early July to mid-November and would be mesotrophic with decrease in temperature. Therefore, a decrease in water quality of the dam reservoir during the warm seasons is expectable. The results indicated that

  7. Dam removal: Listening in

    USGS Publications Warehouse

    Foley, Melissa M.; Bellmore, James; O'Connor, James E.; Duda, Jeff; East, Amy E.; Grant, Gordon G.; Anderson, Chauncey; Bountry, Jennifer A.; Collins, Mathias J.; Connolly, Patrick J.; Craig, Laura S.; Evans, James E.; Greene, Samantha; Magilligan, Francis J.; Magirl, Christopher S.; Major, Jon J.; Pess, George R.; Randle, Timothy J.; Shafroth, Patrick B.; Torgersen, Christian; Tullos, Desiree D.; Wilcox, Andrew C.

    2017-01-01

    Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

  8. Hyporheic Exchange in a Stream Dammed by Beaver: A 1D Simulation with Spatial Energy Head Gradients and Heterogeneous Hydraulic Conductivity as Drivers

    NASA Astrophysics Data System (ADS)

    Fairfax, E. J.; Small, E. E.

    2016-12-01

    Hyporheic exchange, the exchange of water between streams and adjacent subsurface sediments, is an important process connecting groundwater and surface water. Knowing the location and magnitude of hyporheic exchange is useful in evaluating fish spawning habitats, biogeochemical processes, and capacity for aquifer recharge of a given stream. Hyporheic exchange through the streambed is driven by variations in longitudinal head gradient and spatial heterogeneity in hydraulic conductivity. Beaver damming directly effects these two drivers. Beaver dams are efficient flow obstructions that cause significant upstream ponding. Both the flow obstruction itself (the beaver dam) and the pool of deeper water (the beaver pond) increase streambed pressure. Increased streambed pressure alters the energy head gradients within the stream and drives enhanced hyporheic exchange. Additionally, several studies in the literature have found increased sedimentation rates within beaver ponds, particularly of finer particles and organic material that otherwise might not settle out of a faster-moving, undammed stream. This means sediment aggradation along the longitudinal profile of a stream-dam-pond system varies in both volume and type. Nonuniform volume of aggraded sediment further changes streambed topography, and in turn energy head gradients. Nonuniform sediment type results in heterogeneous hydraulic conductivity - the other driver of enhanced hyporheic exchange. We use a 1D model of hyporheic exchange based on Laplace's Equation and Darcy's Equation for a system at steady-state. We utilize observed and theoretical streambed profiles in streams dammed by beaver to explore how the hyporheic exchange in a stream might change through time after a beaver dam is built. The model produces a series of steady-state snapshots of the stream-dam-pond system through time. The simulations demonstrate that on relatively short timescales (months-years) beaver damming can lead to more pronounced

  9. The study of recirculating aquaculture system in pond and its purification effect

    NASA Astrophysics Data System (ADS)

    Qu, Jiangqi; Zhang, Qingjing; Jia, Chengxia; Liu, Pan; Yang, Mu

    2017-05-01

    In this paper, a recirculating aquaculture purification system (RAPS) was designed to solve the problems of aquaculture pollution and shortage of freshwater resource according to the characteristic of northern freshwater ponds of China. The system were arranged in series and composed of high density culture pond, deposit pond, floating and submerged plant pond, ecological floating bed pond and biofilm filtrate pond. At the fish density of 20~30kg/m3 in the high density culture pond, the water quality parameters were monitored seasonally. The results indicated that the removal rate of total nitrogen, total phosphorus, ammonia nitrogen and nitrite nitrogen in the recirculating aquaculture system were 69.59%, 77.89%, 72.54% and 68.68%, respectively. The floating and submerged plant pond and ecological floating bed pond can remove TN and TP obviously, and increase dissolved oxygen and transparency significantly. And the biofilm filtrate pond has good effect of removing ammonium nitrogen and nitrite nitrogen, meanwhile, the microbial communities in the recirculating aquaculture system regulate on the water quality. Therefore, the RAPS show significant effects on water saving and pollution emission reducing.

  10. 6. VIEW OF DAM 83, SHOWING OUTLET CHANNEL FLOWING INTO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF DAM 83, SHOWING OUTLET CHANNEL FLOWING INTO POND A WITH DIVERSION GATES LONG EAST (LEFT) SIDE OF OUTLET CHANNEL, LOOKING SOUTH FROM DOWNSTREAM FACE OF THE DAM - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  11. 29. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. View from downstream of intake, dam wind wall to right, lower wall of overflow chute in left foreground (contains pipes and small dam, possibly for water pumping). West 320 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  12. 2. VIEW OF POND B, LOOKING NORTHEAST FROM THE WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF POND B, LOOKING NORTHEAST FROM THE WEST SIDE OF THE SOURIS RIVER VALLEY, DUE SOUTH OF THE LOOKOUT TOWER - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Surrey (England), ND

  13. Etching characteristic studies for the detection of alpha particles in DAM-ADC nuclear track detector

    NASA Astrophysics Data System (ADS)

    El-Samman, H.; Ashry, A. H.; Arafa, W.; Abou-leila, M.; Abdalla, A. M.; Tsuruta, T.

    2014-09-01

    This study reports the characteristic studies for the detection of alpha particles in DAM-ADC nuclear track detector. Several important parameters that control the track formation such as, the bulk etch rate (VB), track etching rate (VT), dependence of VB and VT on etching concentration and temperature have been extensively studied. The activation energy (Eb) of the bulk etching rate for the DAM-ADC sheets has been calculated, the dependence of etching efficiency and sensitivity upon etchant concentrations and temperature has been investigated, registration efficiency of DAM-ADC detector etched at the optimum etching condition has been examined. The detailed studied results presented in this study provide various useful information about the mechanism of track formation in polymers.

  14. Laboratory study on metal attenuation capacity of fine grained soil near ash pond site.

    PubMed

    Ghosh, Sudipta; Mukherjee, Somnath; Sarkar, Sujoy; Kumar, Sunil

    2008-10-01

    Waste settling tanks of earthen containment nature are common in India for disposal of solid waste in slurry form. For a large pond system, e.g. ash slurry disposal tank of coal base thermal power plant, leachate generation and its migration pose a serious problem. A natural attenuation of controlling the migratory leachate is to use locally available clay material as lining system due to the adsorption properties of soil for reducing some metallic ions. The present investigation was carried out to explore the Ni2+ and Cr6+ removal capacity of surrounding soil of the ash pond site of Super Thermal Power Plant in West Bengal, India through some laboratory scale and field studies. The soil and water samples collected from the site showed the existence of Ni2+ and Cr6+ in excess to permissible limit. A two-dimensional adsorption behaviour of these pollutants through soil was assessed. The results showed that more than 80% of nickel and 72% of chromium were found to be sorbed by the soil corresponding to initial concentrations of two ions, i.e. 1.366 mg/L and 0.76 mg/L respectively. The batch adsorption data are tested Langmuir and Freundlich isotherm models and found reasonably fit. Breakthrough adsorption study uptake also showed a good adsorption capacity of the soil. The experimental results found to fit well with the existing two dimensional (2D) mathematical models as proposed by Fetter (1999).

  15. Experimental study on mechanism and shape characteristics of suspended flexible dam

    NASA Astrophysics Data System (ADS)

    Wang, Jian-zhong; Fan, Hong-xia; Zhu, Li-jun

    2014-12-01

    Hydraulic structures such as groin, longitudinal dike and seawall are common in water conservancy and water transportation engineering projects at home and abroad, which have long been dominated by solid mass structural form. With brush and stone as building materials, this kind of structure has an obvious engineering effect. However, it not only requires huge capital investments, but also has negative impacts on the ecological environment. The suspended flexible dam is an innovative engineering measure, and few theoretical and experimental researches of this type dam can be found at present. This paper studies the mechanism and shape characteristics of this dam and obtains the dynamic equilibrium equation of flexible dam, the float buoyancy expression, and the condition for transformation among three forms of the underwater shape of the dam. The results are valuable in engineering application and can be used as the reference for the future work due to the distinctive design philosophy, the small negative effects on environment and the consistency for sustainable development.

  16. The impact of damming on riverine fluxes to the ocean: A case study from Eastern Iceland.

    PubMed

    Eiriksdottir, Eydis Salome; Oelkers, Eric H; Hardardottir, Jorunn; Gislason, Sigurdur Reynir

    2017-04-15

    Anthropogenic water management has extensively altered the world's river systems through impoundments and channel diversions to meet the human's need for water, energy and transportation. To illuminate the effect of such activities on the environment, this study describes the impact of the installation of the Kárahnjúkar Dam in Eastern Iceland on the transport of riverine dissolved- and particulate material to the ocean by the Jökulsá á Dal and the Lagarfljót rivers. This dam, completed in 2007, collects water into the 2.2 km(3) Hálslón reservoir and diverts water from the glacial Jökulsá á Dal river into the partially glaciated Lagarfljót lagoon via a headrace tunnel. The impact of the damming was evaluated by sampling water from both the Jökulsá á Dal and the Lagarfljót rivers over a 15 year period spanning from 1998 to 2013. The annual flux of most dissolved elements increased substantially due to the damming. The fluxes of dissolved Zn, Al, Co, Ti and Fe increased most by damming; these fluxes increased by 46-391%. These differences can be attributed to changed saturation states of common secondary minerals in the Jökulsá á Dal due to reduced discharge, increased residence time and dissolution of suspended material, and, to a lesser degree, reduced photosynthesis due to less transparency in the Lagarfljót lagoon. The removal of particulate material and thus decreasing adsorption potential in the Jökulsá á Dal is the likely reason for the Fe flux increase. In contrast, approximately 85% of the original riverine transported mass of particulate material is trapped by the dam; that which passes tends to be relatively fine grained, increasing the average specific surface area of that which continues to flow towards the ocean. Consequently, the particulate geometric surface area flux is decreased by only 50% due to the damming. The blooming of silica diatoms during the spring consumes dissolved silica from the coastal waters until it becomes

  17. Bioreactor studies predict whole microbial population dynamics in oil sands tailings ponds.

    PubMed

    Chi Fru, Ernest; Chen, Michael; Walshe, Gillian; Penner, Tara; Weisener, Christopher

    2013-04-01

    Microorganisms in oil sands fluid fine tailings (FFT) are critical to biogeochemical elemental cycling as well as to the degradation of residual hydrocarbon constituents and subsequent methane and CO2 production. Microbial activity enhances particulate matter sedimentation rates and the dewatering of FFT materials, allowing water to be recycled back into bitumen extraction. A bulk of this evidence comes from bioreactor studies and has implications for engineering and environmental management of the FFT ponds. Yet, it is largely uncertain whether such laboratory populations are representative of whole field scale microbial communities. By using population ecology tools, we compared whole microbial communities present in FFT bioreactors to reference populations existing in Syncrude's West In Pit (WIP) tailings pond. Bacteria were found to be persistent in a sulfidic zone in both the oxic and anoxic bioreactors at all occasions tested. In contrast to the WIP, archaea only became predominant in bioreactors after 300 days, at which point analysis of similarity (global R statistic p<0.5) revealed no significant dissimilarities between the populations present in either system. A whole community succession pattern from bacterial dominated prevalence to a new assemblage predominated by archaea was suggested. These results have implications for the stepwise development of microbial model systems for predictive management of field scale FFT basins.

  18. 75 FR 7469 - Whitman River Dam, Inc.; Notice of Intent To File License Application, Filing of Pre-Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-19

    ... Energy Regulatory Commission Whitman River Dam, Inc.; Notice of Intent To File License Application...: Whitman River Dam, Inc. e. Name of Project: Crocker Pond Project. f. Location: The project would be located at the existing Crocker Pond Dam, on the Whitman River, in Worcester County, Massachusetts....

  19. Synthesis of juvenile salmonid passage studies at The Dalles Dam volume II: 2001 - 2005

    USGS Publications Warehouse

    Johnson, G.E.; Beeman, J.W.; Duran , I.N.; Puls, A.L.

    2007-01-01

    The overall goal of juvenile salmonid research at The Dalles Dam is to provide data to inform decisions on strategies to improve smolt survival rates at the project. Survival improvement strategies address the three primary passage routes at The Dalles Dam -- spillway, sluiceway, and turbines – with the general intent to increase spill and sluice passage and decrease turbine passage. From 2001, when Ploskey et al. (2001a) completed their review of 1982-2000 research, through 2005, the USACE has funded over $20M of research in at least 40 studies. The purpose of this current review is to synthesize juvenile salmonid passage data at The Dalles Dam (TDA) collected from 2001 through 2005.

  20. Brief reconnaissance study for the addition of hydropower for Craggy Dam, Asheville, North Carolina

    SciTech Connect

    Gebhard, T.G. Jr.

    1982-02-08

    The feasibility of retrofitting the Craggy Dam near Asheville, NC for power generation was examined. This dam has a developable head of 23 ft., was built in 1903 for electric power generation, and is currently unused. The study of environmental, institutional, safety and economic factors showed that hydroelectric power development at this site is feasible, that more power can be produced than can be used by the owner, i.e., the Metropolitan Sewer District of Asheville, and that excess power can be sold to the Carolina Power and Light Co. (LCL)

  1. Hydraulic characteristics and dynamics of beaver dams in a Midwestern U.S. agricultural waershed

    Treesearch

    M.C. McCullough; D.E. Eisenhauer; M.G. Dosskey; D.M. Admiraal

    2006-01-01

    Populations of Noth America beaver (castor canadensis) have increased in the past decades throughout the Midwestern U.S., leading to an increase in the frequency of beaver dams in small streams. Beaver dams form ponds and slow water velocity. Multiple dams create a stair-step effect on the water surface profile. The hydraulic and geomorphic influence of beaver dams on...

  2. Measuring Taste Impairment in Epidemiologic Studies – The Beaver Dam Offspring Study

    PubMed Central

    Cruickshanks, KJ; Schubert, CR; Snyder, DJ; Bartoshuk, LM; Huang, GH; Klein, BEK; Klein, R; Nieto, FJ; Pankow, JS; Tweed, TS; Krantz, EM; Moy, GS

    2008-01-01

    Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiological studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiological studies is challenging and requires repeatable, efficient methods which can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin are eligible for this on-going study. The parents were residents of Beaver Dam and 43–84 years of age in 1987–88; offspring range in age from 21–84 years in 2005–2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented. PMID:19686191

  3. Evaluation of 3D Ground Penetrating Radar Efficiency for Abandoned Tailings Pond Internal Structure Analysis and Risk Assessment

    NASA Astrophysics Data System (ADS)

    Cortada, Unai; Martínez, Julián; Hidalgo, Mª Carmen; Rey, Javier

    2017-04-01

    Evaluation of 3D Ground Penetrating Radar Efficiency for Abandoned Tailings Pond Internal Structure Analysis and Risk Assessment Abandoned tailings ponds constitute a severe environmental problem in old Pb mining districts due to their high contents in metallic and semi-metallic elements. In most of the cases, there is a lack of information about the construction procedures and the previous environmental situation, which hinders the environmental risk evaluation. In these cases, Ground Penetrating Radar (GPR) could be an interesting technique to analyze the internal structure of the tailings ponds and detect vulnerable zones for leaching processes. Consequently, the GPR could help in the abandoned tailings ponds environmental risk assessment. In this study, a GPR 3D campaign was carried out with a 250 MHz frequency antenna in order to evaluate the efficiency of this technique in both the analysis of internal structures and the environmental risk assessment. Subsequently, 2D and 3D models were undertaken to represent graphically the obtained results. The studied tailings pond is located in the Guadiel river bank, a water course draining the mining district of Linares, Spain. The dam is 150 m length and 80 m width. The GPR 3D was done in a selected area near the central part of the pond. The analyzed grid was 25x50 m and the spacing of the slides was 1 m. The study revealed that the contact between the tailings and the substratum is located at 2.5 m. No intermediate layer was found, which means that the tailings pond was heightened on the fluvial terrace without any insulation system. Inside the first meter of the pond, a cross stratification was identified. The orientation of those laminations changed with the depth, which means that the stockpiling was performed from the different sides of the tailings pond. Furthermore, the direction of these stratifications is slightly concentric to the middle of the dam which could be associated with a central drainage system

  4. Operation of a pond-cooler: the case of Berezovskaya GRES-1

    NASA Astrophysics Data System (ADS)

    Morozova, O. G.; Kamoza, T. L.; Koyupchenko, I. N.; Savelyev, A. S.; Pen, R. Z.; Veselkova, N. S.; Kudryavtsev, M. D.

    2017-08-01

    Pond-coolers at heat and nuclear power stations are natural-technological systems, so the program of their monitoring should include the effect made by the SRPS (state regional power station) on the pond ecosystem, including thermal discharge of cooling water. The objectives of this study were development and implementation of a monitoring program for the cooling pond of Berezovskaya SRPS-1 on the chemical and biological water quality indicators and identification of patterns of the thermal and hydrochemical regime when operating the progressive power plant (from 1996 to 2015). The quality of the cooling water of the pond-cooler BGRES-1 was studied under full-scale conditions by selecting and analyzing the water samples of the pond in accordance with the principles of complexity, systematic observation, and consistency of timing their conduct with the characteristic hydrological phases. Processing of the obtained array of monitoring data by methods of mathematical statistics makes it possible to identify the main factors affecting the water quality of the pond. The data on water quality obtained during their monitoring and mathematical processing over a long time interval are the scientific basis for forecasting the ecological state of the pond, which is necessary to economically ensure the efficient energy production and safety of water use. Recommendations proposed by these authors, including those partially already implemented, have been to prevent the development of eutrophication processes in the pond-cooler: the construction of a dam that cuts off the main peat massif and cleaning the river banks forming the cooling pond.

  5. 12. Upstream view showing thelower log pond log chute in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Upstream view showing thelower log pond log chute in the main channel of the Hudson River. The log chute in the dam can be seen in the background. Facing southwest. - Glens Falls Dam, 100' to 450' West of U.S. Route 9 Bridge Spanning Hudson River, Glens Falls, Warren County, NY

  6. A study of suspended solids in the Requena Dam by remote sensing

    NASA Technical Reports Server (NTRS)

    Azuara, P. R.; Hidalgo, L. L.

    1977-01-01

    Remote sensing was applied to a preliminary study of suspended solids in the Requena Dam. Aerial and terrestrial photographs were analyzed by photointerpretation and microdensitometry. Field measurements and sampling were also made. A relationship between ground data for the concentration of suspended solids and the transmissibility of the aerial infrared film was suggested.

  7. Appropriate small dam management for minimizing catchment-wide safety threats: International benchmarked guidelines and demonstrative cases studies

    NASA Astrophysics Data System (ADS)

    Pisaniello, John D.; Tingey-Holyoak, Joanne; Burritt, Roger L.

    2012-01-01

    Small dam safety is generally being ignored. The potential for dam failure resulting in catastrophic consequences for downstream communities, property, and the environment, warrants exploration of the threats and policy issues associated with the management of small/farm dams. The paper achieves this through a comparative analysis of differing levels of dam safety assurance policy: absent, driven, strong, and model. A strategic review is undertaken to establish international dam safety policy benchmarks and to identify a best practice model. A cost-effective engineering/accounting tool is presented to assist the policy selection process and complement the best practice model. The paper then demonstrates the significance of the small-dam safety problem with a case study of four Australian States,policy-absent South Australia, policy-driven Victoria, policy-strong New South Wales, and policy-modelTasmania. Surveys of farmer behavior practices provide empirical evidence of the importance of policy and its proper implementation. Both individual and cumulative farm dam failure threats are addressed and, with supporting empirical evidence, the need for "appropriate" supervision of small dams is demonstrated. The paper adds to the existing international dam policy literature by identifying acceptable minimum level practice in private/farm dam safety assurance policy as well as updated international best practice policy guidelines while providing case study demonstration of how to apply the guidelines and empirical reinforcement of the need for "appropriate" policy. The policy guidelines, cost-effective technology, and comparative lessons presented can assist any jurisdiction to determine and implement appropriate dam safety policy.

  8. Impact of earthquake-induced dammed lakes on channel evolution and bed mobility: Case study of the Tsaoling landslide dammed lake

    NASA Astrophysics Data System (ADS)

    Hsu, Yin-Sung; Hsu, Yu-Hsiung

    2009-07-01

    SummaryOn May 12, 2008, a mega earthquake measuring 8.0 on the Richter scale hit Wenchuan, Sichuan province of China, causing severe casualties and damages. The tremor was felt by nearly all of Asia. The quake-induced landslides and sliding slopes also formed 34 dammed lakes of various sizes, each of which may bring serious potential disasters. Understandably, the earthquake-triggered dammed lakes and their ensuing disasters cause grave concerns worldwide. Similar devastation took place in Taiwan on September 21, 1999, when an earthquake of 7.3 on the Richter scale occurred with the epic center at Jiji in central Taiwan. The earthquake affected changes in the channel course and induced landslides to form several dammed lakes, among which a large dammed lake was created in the upstream Chingshui River with reservoir capacity of 42,000,000 m 3. Its size and potential problems therefore caused serious apprehension. A series of subsequent typhoon-induced torrential flooding events affected the channel forming processes to diverge drastically between the dammed lake and the landslide area, which presented a rare phenomenon for data observation and research. In the last century five dammed lakes had been formed in the area due to landslides, suggesting high possibility of future recurrence, particularly from earthquake activities. An investigation of the channel evolution in this area prior and post a quake, therefore, can assist in current disaster handling protocols and provide policy guidelines for future crisis management when landslides occur. Topographic changes in the study watershed, historical channel surveys, and past studies were gathered to aid the geomorphologic analysis. Channel evolution in the Tsaoling dammed lake and the landslide area was also investigated using a NETSTARS channel scour-deposition model by simulating the trends of erosion and deposition patterns under the influence of different recurrence interval flood peaks and streamflow time series

  9. Evaluation of the pseudostatic analyses of earth dams using Fe simulation and observed earthquake-induced deformations: case studies of Upper San Fernando and Kitayama dams.

    PubMed

    Akhlaghi, Tohid; Nikkar, Ali

    2014-01-01

    Evaluation of the accuracy of the pseudostatic approach is governed by the accuracy with which the simple pseudostatic inertial forces represent the complex dynamic inertial forces that actually exist in an earthquake. In this study, the Upper San Fernando and Kitayama earth dams, which have been designed using the pseudostatic approach and damaged during the 1971 San Fernando and 1995 Kobe earthquakes, were investigated and analyzed. The finite element models of the dams were prepared based on the detailed available data and results of in situ and laboratory material tests. Dynamic analyses were conducted to simulate the earthquake-induced deformations of the dams using the computer program Plaxis code. Then the pseudostatic seismic coefficient used in the design and analyses of the dams were compared with the seismic coefficients obtained from dynamic analyses of the simulated model as well as the other available proposed pseudostatic correlations. Based on the comparisons made, the accuracy and reliability of the pseudostatic seismic coefficients are evaluated and discussed.

  10. Evaluation of the Pseudostatic Analyses of Earth Dams Using FE Simulation and Observed Earthquake-Induced Deformations: Case Studies of Upper San Fernando and Kitayama Dams

    PubMed Central

    Akhlaghi, Tohid

    2014-01-01

    Evaluation of the accuracy of the pseudostatic approach is governed by the accuracy with which the simple pseudostatic inertial forces represent the complex dynamic inertial forces that actually exist in an earthquake. In this study, the Upper San Fernando and Kitayama earth dams, which have been designed using the pseudostatic approach and damaged during the 1971 San Fernando and 1995 Kobe earthquakes, were investigated and analyzed. The finite element models of the dams were prepared based on the detailed available data and results of in situ and laboratory material tests. Dynamic analyses were conducted to simulate the earthquake-induced deformations of the dams using the computer program Plaxis code. Then the pseudostatic seismic coefficient used in the design and analyses of the dams were compared with the seismic coefficients obtained from dynamic analyses of the simulated model as well as the other available proposed pseudostatic correlations. Based on the comparisons made, the accuracy and reliability of the pseudostatic seismic coefficients are evaluated and discussed. PMID:24616636

  11. Modelling the Effects of Land-Use Changes on Climate: a Case Study on Yamula DAM

    NASA Astrophysics Data System (ADS)

    Köylü, Ü.; Geymen, A.

    2016-10-01

    Dams block flow of rivers and cause artificial water reservoirs which affect the climate and the land use characteristics of the river basin. In this research, the effect of the huge water body obtained by Yamula Dam in Kızılırmak Basin is analysed over surrounding spatial's land use and climate change. Mann Kendal non-parametrical statistical test, Theil&Sen Slope method, Inverse Distance Weighting (IDW), Soil Conservation Service-Curve Number (SCS-CN) methods are integrated for spatial and temporal analysis of the research area. For this research humidity, temperature, wind speed, precipitation observations which are collected in 16 weather stations nearby Kızılırmak Basin are analyzed. After that these statistical information is combined by GIS data over years. An application is developed for GIS analysis in Python Programming Language and integrated with ArcGIS software. Statistical analysis calculated in the R Project for Statistical Computing and integrated with developed application. According to the statistical analysis of extracted time series of meteorological parameters, statistical significant spatiotemporal trends are observed for climate change and land use characteristics. In this study, we indicated the effect of big dams in local climate on semi-arid Yamula Dam.

  12. A long-term monitoring study of chlorophyll, microbial contaminants, and pesticides in a coastal residential stormwater pond and its adjacent tidal creek.

    PubMed

    DeLorenzo, Marie E; Thompson, Brian; Cooper, Emily; Moore, Janet; Fulton, Michael H

    2012-01-01

    Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to water-quality problems including nutrient enrichment, chemical contamination, and bacterial contamination. This study presents 5 years of monitoring data assessing water quality of a residential subdivision pond and adjacent tidal creek in coastal South Carolina, USA. The stormwater pond is eutrophic, as described by elevated concentrations of chlorophyll and phosphorus, and experiences periodic cyanobacterial blooms. A maximum monthly average chlorophyll concentration of 318.75 μg/L was measured in the stormwater pond and 227.63 μg/L in the tidal creek. Fecal coliform bacteria (FCB) levels were measured in both the pond and the tidal creek that exceeded health and safety standards for safe recreational use. A maximum monthly average FCB level of 1,247 CFU/100 mL was measured in the stormwater pond and 12,850 CFU/100 mL in the tidal creek. In addition, the presence of antibiotic resistant bacteria and pathogenic bacteria were detected. Low concentrations of herbicides (atrazine and 2,4-D: ), a fungicide (chlorothalonil), and insecticides (pyrethroids and imidacloprid) were measured. Seasonal trends were identified, with the winter months having the lowest concentrations of chlorophyll and FCB. Statistical differences between the stormwater pond and the tidal creek were also noted within seasons. The tidal creek had higher FCB levels than the stormwater pond in the spring and summer, whereas the stormwater pond had higher chlorophyll levels than the tidal creek in the summer and fall seasons. Chlorophyll and FCB levels in the stormwater pond were significantly correlated with monthly average temperature and total rainfall. Pesticide concentrations were also significantly correlated with temperature and rainfall. Pesticide concentrations in the stormwater pond were significantly correlated with

  13. Modelling the impact of dam removal on geomorphic channel response and sediment delivery: an Austrian case study

    NASA Astrophysics Data System (ADS)

    Pöppl, Ronald; Coulthard, Tom; Keesstra, Saskia; Keiler, Margreth

    2015-04-01

    Dams are often considered to have the most significant impact on rivers as dam construction generally reduces downstream sediment fluxes which further involves geomorphic changes in the affected river reaches. Since many dams no longer fulfill their intended purpose (e.g. due to siltation), are dangerous (e.g. catastrophic dam failures) and/or are ecologically damaging (e.g. habitat destruction), within the last two decades several dams have been removed and many more are already proposed for removal. Unfortunately, there is still only little empirical knowledge about the geomorphic consequences of dam removals and the related sediment release which represents a big challenge for river management. Modelling is one way to approach this problem. In the presented study we modelled the impacts of dam removal on geomorphic channel processes, channel morphology and sediment delivery further considering the role of channel engineering measures and reservoir excavation within a river reach impacted by a series of dams using the landscape evolution model CAESAR-Lisflood. The model was run with data from a small catchment located in Lower Austria. Modelled geomorphic channel changes and sediment fluxes were spatio-temporally analyzed, related to real-world data and are discussed in the context of river management issues.

  14. Social impacts of large dam projects: a comparison of international case studies and implications for best practice.

    PubMed

    Tilt, Bryan; Braun, Yvonne; He, Daming

    2009-07-01

    This paper applies the tool of social impact assessment (SIA) to understand the effects of large dam projects on human communities. We draw upon data from two recent SIA projects: the Lesotho Highlands Water Project in Southern Africa, and the Manwan Dam, located on the upper Mekong River in southwestern China. These two cases allow us to examine the social impacts of large dam projects through time and across various geographical scales. We focus on a range of social impacts common to many large-scale dam projects, including: the migration and resettlement of people near the dam sites; changes in the rural economy and employment structure; effects on infrastructure and housing; impacts on non-material or cultural aspects of life; and impacts on community health and gender relations. By identifying potential impacts in advance of a large dam project, agencies and policymakers can make better decisions about which interventions should be undertaken, and how. We conclude our analysis with an overview of lessons learned from the case studies and suggestions for best practice in assessing the social impacts of large dams. Conducting proper social impact assessments can help to promote development strategies that address the most important concerns for local populations, enhancing the long-term sustainability of dam projects.

  15. Percolation pond as a method of managed aquifer recharge in a coastal saline aquifer: A case study on the criteria for site selection and its impacts

    NASA Astrophysics Data System (ADS)

    Christy, Raicy Mani; Lakshmanan, Elango

    2017-07-01

    Percolation ponds have become very popular methods of managed aquifer recharge due to their low cost, ease of construction and the participation and assistance of community. The objective of this study is to assess the feasibility of a percolation pond in a saline aquifer, north of Chennai, Tamil Nadu, India, to improve the storage and quality of groundwater. Electrical resistivity and ground penetrating radar methods were used to understand the subsurface conditions of the area. From these investigations, a suitable location was chosen and a percolation pond was constructed. The quality and quantity of groundwater of the nearby area has improved due to the recharge from the pond. This study indicated that a simple excavation without providing support for the slope and paving of the bunds helped to improve the groundwater quality. This method can be easily adoptable by farmers who can have a small pond within their farm to collect and store the rainwater. The cost of water recharged from this pond works out to be about 0.225 Re/l. Cleaning the pond by scrapping the accumulated sediments needs to be done once a year. Due to the small dimension and high saline groundwater, considerable improvement in quality at greater depths could not be achieved. However, ponds of larger size with recharge shafts can directly recharge the aquifer and help to improve the quality of water at greater depths.

  16. ERT studies on tailings ponds of the Sierra Minera Cartagena-La Union, SE Spain (Invited)

    NASA Astrophysics Data System (ADS)

    Martinez-Pagan, P.; Faz-Cano, A.; Rosales-Aranda, M. R.

    2009-12-01

    The Sierra Minera Cartagena - La Union (SE Spain) is a huge area that has been mined for centuries. That mining extraction activity was particularly enormous in the second half of the twentieth century. By the early 1980’s almost all mineral deposits of this area had been depleted and the mineral processing plants had left 80 tailings ponds of different shape and height as a result of their activity. At the present, these former mining areas are close to important urban and industrial centers, where the tailings ponds are potential points of environmental and geotechnical concerns among others. In the 1972, there was also an important collapse of a tailings pond after a strong stormy event. Because of that, nowadays, there are several researcher groups working on the area with the goal of improving the environmental, geotechnical, safety, and use conditions of the tailings ponds. In this framework, the electrical resistivity tomography (ERT) method was used to obtain complementary information from the inner of the tailings ponds itself. Due to the high electrical resistivity contrast between the tailings and the hard-rock the geo-electrical methods became very useful in getting information about the bedrock geometry. In addition, where the tailing ponds have not been built up with a more complex interne structure (Figure 1) then it has been possible to obtain their construction history based on the grain distribution which is related in some extent to the electrical resistivity. In some cases, based on the fact of the presence of big cracks into the pond as pathways (Figure 2) where the mine acid waters are infiltrated easily, the use of ERT technique has proved its usefulness in highlighting them. Moreover, the ERT method can be an interesting tool in tailings ponds remediation works by delimiting the acid areas on the surface characterized by low electrical resistivity values.

  17. A preliminary observation on water quality and plankton of an earthen fish pond in Bangladesh: recommendations for future studies.

    PubMed

    Hossain, Md Yeamin; Jasmine, Saleha; Ibrahim, Abu Hanif Md; Ahmed, Zoarder Faruque; Ohtomi, Jun; Fulanda, Bernerd; Begum, Momtaz; Mamun, Abdullahil; El-Kady, Mohamed A H; Wahab, Md Abdul

    2007-03-15

    The present study provides a characterization of water quality and plankton samples in earthen fish pond in Rajshahi, Bangladesh. Sampling was done over a period of six months, running from October, 2004 through March, 2005. All the water quality parameters were within the optimal ranges for plankton productivity. Temperatures varied from 19.75 to 27.25 degrees C; transparency, 24.75-29.50 cm; pH, 6.62-7.85; Dissolved Oxygen (DO), 3.87-5.85 mg L(-1); free CO2 5.25-7.25 mg L(-1) and bicarbonate (HCO3) alkalinity, 81.25-147.5 mg L(-1). Analyses of plankton samples recorded a total of 5 classes phytoplankton viz.; Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae and 2 classes of zooplankton; Crustacea and Rotifera. The phytoplankton population was comprised of 17 genera belonging to Cyanophyceae (5 classes, 34.47%), Bacillariophyceae (3, 13.87%), Cyanophyceae (3, 34.48%), Euglenophyceae (3, 10.68%) and 1 to Dinophyceae (6.50%). The zooplankton population consisted of 10 genera belonging to Rotifera (4, 40.13%) and Crustacea (6, 59.87%). Phytoplankton and zooplankton abundance varied from 60800 to 239400 units/l and 7620 to 12160 units/l, respectively. It is concluded that the phytoplankton groups provide the main support for earthen pond aquaculture in the pond compared to zooplankton classes. The information provides for more research to compare water quality and pond plankton characteristics in earthen aquaculture systems with and without fish stocking. Further studies on the seasonal changes of water quality parameters and its effects on plankton production in the fish ponds and all year extended monitoring is recommended in future studies.

  18. Dissolved organic carbon characteristics in surface ponds from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China

    NASA Astrophysics Data System (ADS)

    Wang, L. L.; Song, C. C.; Yang, G. S.

    2013-01-01

    Dissolved organic carbon (DOC) is a significant component of carbon and nutrient cycling in fluvial ecosystems. Natural wetlands, as important DOC sources for river and ocean ecosystems, have experienced extensive natural and anthropogenic disturbances such as climate change, hydrological variations and land use change in recent years. The DOC characteristics in surface ponds from contrasting wetlands in the Sanjiang Plain, Northeastern China were investigated. Surface ponds at seven sites (two natural phialiform wetlands, three natural riparian wetlands, one degraded wetland and one artificial wetland, i.e., rice paddy) were monitored during the growing seasons of 2009 and 2010. The results show that the surface ponds at the five natural wetland sites exhibited a wide range of DOC concentrations (10.06-48.73 mg L-1) during the study period. The DOC concentrations showed no annual differences (P > 0.05) at all the wetland sites, except one of the phialiform wetland sites. The two phialiform wetlands exhibited higher DOC concentrations than the three riparian wetlands (P < 0.05). The DOC concentration in the surface pond at the artificial wetland site was relatively low (P < 0.05) compared to that at the degraded wetland site. The C/C ratios (the color per carbon unit ratio, Abs400/DOC concentration) showed inconsistent variations among these seven wetland sites, while the E4/E6 ratio (Abs465/Abs665, fulvic acid/humic acid) from the surface pond in the rice paddy land exerted 42.07-55.36% reductions (P < 0.05), compared to those at the five natural wetland sites. Furthermore, the E4/E6 ratio in the surface pond at the rice paddy site was significantly lower compared to that at the degraded wetland site (P < 0.05), which indicated that disturbance to wetland DOC in surface ponds might be stronger when natural wetlands were converted to rice paddies in comparison with wetland degradation. This study could not only provide insightful points for understanding the

  19. Solar pond

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1978-01-01

    Shallow pools of liquid to collect low-temperature solar generated thermal energy are described. Narrow elongated trenches, grouped together over a wide area, are lined with a heat-absorbing black liner. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethlene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out ultraviolet radiation and trap in infrared radiation.

  20. The Pond Is Our Laboratory

    ERIC Educational Resources Information Center

    Marchewka, Barbara Turco

    1978-01-01

    This science teacher's laboratory is a pond within walking distance of his school that provides a stimulating environment for exploring the natural world. With simple materials students practice making careful observations, taking measurements and compiling and graphing information for their science studies. They also extend their pond experiences…

  1. Dam Removal Provides Fish Passage, Water Quality Benefits

    EPA Pesticide Factsheets

    The Bishopville Pond Dam in Maryland has been replaced with a series of pools, runs and step-like structures, improving water quality downstream and providing access for key fish species to spawn upstream.

  2. Impact assessment of gilgel gibe hydroelectric dam on schitosomiasis: a cross sectional study in southwest ethiopia.

    PubMed

    Yami, Alemeshet; Kebede, Sileshi; Mamo, Yoseph

    2010-07-01

    Intestinal schistosomiasis is prevalent in East Africa including Ethiopia. Constructed five years back, Gilgel Gibe dam is suspected to harbor the intermediate host for transmission of schistosomiasis. The objective of this study was to determine the prevalence of intestinal schistosomiasis and risk factors among school children. A comparative cross-sectional study was carried out in October 2008 in four Woredas bordering Gilgel Gibe dam, within 10 kilometers, and Bulbul, which is 30 Kms away from the dam. Children attending grades 1-8 in the schools located adjacent to the dam constituted the cases and those living in Bulbul constitute the controls. Using Epinfo version 6.0 for cross-sectional study, a sample size of 937 was determined. Sample size allocation was done 2:1 for cases and control. After interview, stool sample was collected and analyzed. Screening for the presence of intermediate host and physiochemical analyses of selected water bodies along the major water contact sites of the reservoir was also done Data were entered into computer and analyzed using SPSS for windows version 13.0.1. Out of 624 sampled cases and 312 controls, 585 and 270 participated in the study giving a response rate of 93.8% and 86.5%, respectively. Four hundred seventy four (81.0% of the cases and 203 (75.2%) controls use latrine regularly. On stool examination, 406 (47.5%) children, 295 (50.4%) cases and 111 (41.1%) controls) were positive to intestinal parasites but only two children, both from the control groups, were positive for Schistosoma mansoni. The three river water samples on which malacological survey was done had similar physicochemical characteristics in many ways except high conductivity, pH and percent of dissolved oxygen concentration (milligram per liter) at one site where uninfected Biomphilaria Pfeifferi was found The study revealed that schistosomiasis is not yet a problem at Gilgel-Gibe dam. But, continuous surveying is required as the intermediate host is

  3. Suitability of village pond waters for irrigation-a case study from district Ludhiana, India.

    PubMed

    Toor, A S; Khurana, M P S; Sidhu, B S; Khera, Jaspreet Singh; Brar, Kiranvir K

    2011-01-01

    The village ponds were used for storing rainwater for animals and recharging of underground water. Recent developments like public water supply for household purpose, provision of household wastewater concrete channels, and toilet septic tanks have polluted the village ponds. The infiltration of water has decreased due to non-cleaning of silt from the pond beds. Increased discharge of wastewater from households, coupled with a low infiltration rate, has inundated these ponds. People have abandoned the use of this water for animals. An effort has been made to assess the suitability of this water for irrigation in the vicinity so as to clean these ponds. Seventy-eight water samples were collected from the village ponds in the Ludhiana district of Punjab. The samples were analyzed for total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), electrical conductivity (EC), residual sodium carbonate (RSC), nitrogen, water soluble P and K, as well as micronutrients and pollutant elements. The total solids content of these waters were on the higher side. Considering TSS, BOD, and COD, some of these waters are unsafe for their disposal in river or water bodies. Electrical conductivity ranged from 693 to 5050 μmhos/cm, and RSC varied between -1.9 and 22.8 meq/l. The inorganic N (NH+₄+ NO-₃-N) and total Kjeldahl N ranged from 3 to 30 and 8 to 41 mg/l, respectively. The amount of micronutrients (Zn, Cu, Fe, and Mn) present in pond water indicated its high nutrient value. The content of the pollutant elements such as nickel, cadmium, and lead was below the maximum permissible limits, thereby indicating its suitability for irrigation. According to the EC and RSC criteria, 18% of the samples were fit, 31% were marginal, and 51% were unfit for irrigation. The data indicate that these waters are a good source of nutrients for agriculture.

  4. Tailings Pond Characterization And Designing Through Geophysical Surveys In Dipping Sedimentary Formations

    NASA Astrophysics Data System (ADS)

    Muralidharan, D.; Andrade, R.; Anand, K.; Sathish, R.; Goud, K.

    2009-12-01

    two magnetic profiles inside the tailings pond and surrounding areas on the southern part of the tailings pond enabled in identifying two parallel east-west intrusive bodies forming the impermeable boundary for the tailings pond. The shallow seismic refraction and the geophysical studies in and around the proposed tailings pond brought out the suitability of the site, even when the toxic elements percolates through the subsurface formations in to the groundwater system, the existence of dykes on either side of the proposed ponding area won’t allow the water to move across them thus by restricting the contamination within the tailings pond area. Similarly, the delineation of a fault zone within the tailings pond area helped in shifting the proposed dam axis of the pond to avoid leakage through the fault zone causing concern to environment pollution.

  5. Impact of Beaver Pond Colonization History on Methylmercury Concentrations in Surface Water.

    PubMed

    Levanoni, Oded; Bishop, Kevin; Mckie, Brendan G; Hartman, Göran; Eklöf, Karin; Ecke, Frauke

    2015-11-03

    Elevated concentrations of methylmercury (MeHg) in freshwater ecosystems are of major environmental concern in large parts of the northern hemisphere. Beaver ponds have been identified as a potentially important source of MeHg. The role of beavers might be especially pronounced in large parts of Europe, where beaver populations have expanded rapidly following near-extirpation. This study evaluates the role of the age and colonization history (encompassing patterns of use and reuse) of ponds constructed by the Eurasian beaver Castor fiber in regulating MeHg concentrations in Swedish streams. In 12 beaver systems located in three regions, we quantified MeHg concentrations together with other relevant parameters on five occasions per year in 2012-2013. Five were pioneer systems, inundated for the first time since beaver extirpation, and seven were recolonized, with dams reconstructed by newly recolonizing beavers. MeHg concentrations in pioneer but not in recolonized beaver systems were up to 3.5 fold higher downstream than upstream of the ponds, and varied between seasons and years. Our results show that pioneer inundation by beavers can increase MeHg concentrations in streams, but that this effect is negligible when dams are reconstructed on previously used ponds. We therefore expect that the recovery and expansion of beavers in the boreal system will only have a transitional effect on MeHg in the environment.

  6. Beaver dams and overbank floods influence groundwater-surface water interactions of a Rocky Mountain riparian area

    USGS Publications Warehouse

    Westbrook, C.J.; Cooper, D.J.; Baker, B.W.

    2006-01-01

    Overbank flooding is recognized by hydrologists as a key process that drives hydrogeomorphic and ecological dynamics in mountain valleys. Beaver create dams that some ecologists have assumed may also drive riparian hydrologic processes, but empirical evidence is lacking. We examined the influence of two in-channel beaver dams and a 10 year flood event on surface inundation, groundwater levels, and flow patterns in a broad alluvial valley during the summers of 2002-2005. We studied a 1.5 km reach of the fourth-order Colorado River in Rocky Mountain National Park (RMNP), Colorado, USA. The beaver dams and ponds greatly enhanced the depth, extent, and duration of, inundation associated with floods; they also elevate the water table during both high and low flows. Unlike previous studies we found the main effects of beaver on hydrologic processes occurred downstream of the dam rather than being confined to the near-pond area. Beaver dams on the Colorado River caused river water to move around them as surface runoff and groundwater seepage during both high- and low-flow periods. The beaver dams attenuated the expected water table decline in the drier summer months for 9 and 12 ha of the 58 ha study area. Thus we provide empirical evidence that beaver can influence hydrologic processes during the peak flow and low-flow periods on some streams, suggesting that beaver can create and maintain hydrologic regimes suitable for the formation and persistence of wetlands. Copyright 2006 by the American Geophysical Union.

  7. Spatial Multicriteria Decision Analysis of Flood Risks in Aging-Dam Management in China: A Framework and Case Study

    PubMed Central

    Yang, Meng; Qian, Xin; Zhang, Yuchao; Sheng, Jinbao; Shen, Dengle; Ge, Yi

    2011-01-01

    Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites. PMID:21655125

  8. Spatial multicriteria decision analysis of flood risks in aging-dam management in China: a framework and case study.

    PubMed

    Yang, Meng; Qian, Xin; Zhang, Yuchao; Sheng, Jinbao; Shen, Dengle; Ge, Yi

    2011-05-01

    Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites.

  9. Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams).

    PubMed

    Heydari, Mohammad; Othman, Faridah; Taghieh, Mahmood

    2016-01-01

    Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam's location (Series and parallel), conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands.

  10. Claire ponds as an experimental model for Marteilia refringens life-cycle studies: new perspectives.

    PubMed

    Audemard, C; Barnaud, A; Collins, C M.; Le Roux, F; Sauriau, P -G.; Coustau, C; Blachier, P; Berthe, F C.J.

    2001-02-20

    Since its first description, the paramyxean parasite Marteilia refringens (Grizel et al.) has been recognised as a significant pathogen of the European flat oyster Ostrea edulis L. The existence of a complex life-cycle involving several hosts was postulated early on by many authors, although it remains unsolved. Recent developments in the DNA-based diagnosis of M. refringens provides new prospects for the detection of the parasite in potential hosts. However, this screening remains impeded by the number of species living in the vicinity of oyster beds. We report here on the use of semi-closed oyster ponds (so called 'claire' in Marennes-Oléron Bay) as a study model for the life-cycle of M. refringens. Claires are located in an endemic area for M. refringens and transmission of the disease to healthy oysters has been shown to be effective during the course of this study. The environmental characteristics of the claires strongly limit the number of species compared with intertidal areas and oyster beds. Consequently, extensive sampling of a limited number of species cohabiting with oysters was possible. These were preserved for future screening of M. refringens. The experimental model should bring new insights to the life-cycle of M. refringens, as it enables us to propose new conceptual schemes of M. refringens transmission. The role of species as potential hosts is discussed regarding their biology and geographical distribution.

  11. Saltless Solar Ponds

    NASA Technical Reports Server (NTRS)

    Lin, E. I.

    1984-01-01

    Problems associated with heat storage in solar ponds eliminated by transparent insulating cover at surface of pond. Cover makes unnecessary salt gradient that suppresses natural convection within pond to promote thermal storage.

  12. Centrifuge study on volume changes and dynamic stability of earth dams

    SciTech Connect

    Arulanandan, K. ); Seed, H.B. ); Yogachandran, C. ); Muraleetharan, K.K. ); Seed, R.B. ); Kabilamany, K. )

    1993-11-01

    A simplified method of analysis for determining the permanent displacement of a clay core in a heterogeneous earth dam subjected to dynamic excitation is discussed. Centrifuge studies on three identical models were used to determine the deformation characteristics of earth dams subjected to earthquakes large enough to produce flow slides. These studies suggest that the failure mode is considerably influenced by the reduction in shear strength caused by the void-ratio increase and the subsequent decrease in effective stress at the sand-clay interface. Conventional sliding block analysis does not consider this phenomenon. A simplified method using the concepts of critical-state soil mechanics is presented that may be used to estimate both the reduced shear strength and the redistributed void-ratio at the interface. Values predicted using this method were found to agree well with those observed in the centrifuge experiments. By integrating these quantities into Newmark's sliding block analysis, a better estimate of the permanent displacement of an earth dam may be obtained.

  13. Experimental study on the dam-break hydrographs at the gate location

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Liu, Haijiang; Guo, Liheng; Lu, Senxun

    2017-08-01

    When studying the dam-break flow phenomenon, the basic hydrodynamic features of the dam-break flow at the gate location should be verified primarily. In this study, laboratory experiments were performed in a rectangular and horizontal flume with the same initial water head setting on the dry and wet downstream bed conditions. Water surface elevation was extracted through image analysis and validated by comparing with the data measured using a wave gauge. Temporal variation of the water surface elevation at the gate location, quantified in terms of high-speed video recorded images, can be divided into three stages, the sharp decreasing stage, the relatively steady stage, and the gradually decreasing stage. Applicability of several classic analytical solutions of the dam-break problem at the gate location was validated using present experimental data. Ritter's solution is effective for the dry bed condition while Stoker's solution could be applied to the wet bed case, and both are only applicable during the steady stage. Lin' solution reproduces the gate-site hydrographs well during both the relatively steady and the gradually decreasing stages, especially for the condition under which the down-upstream water depth ratio is smaller than 0.138.

  14. Buoyancy studies in natural communities of square gas-vacuolate archaea in saltern crystallizer ponds.

    PubMed

    Oren, Aharon; Pri-El, Nuphar; Shapiro, Orr; Siboni, Nachshon

    2006-04-14

    Possession of gas vesicles is generally considered to be advantageous to halophilic archaea: the vesicles are assumed to enable the cells to float, and thus reach high oxygen concentrations at the surface of the brine. We studied the possible ecological advantage of gas vesicles in a dense community of flat square extremely halophilic archaea in the saltern crystallizer ponds of Eilat, Israel. We found that in this environment, the cells' content of gas vesicles was insufficient to provide positive buoyancy. Instead, sinking/floating velocities were too low to permit vertical redistribution. The hypothesis that the gas vesicles enable the square archaea to float to the surface of the brines in which they live was not supported by experimental evidence. Presence of the vesicles, which are mainly located close to the cell periphery, may provide an advantage as they may aid the cells to position themselves parallel to the surface, thereby increasing the efficiency of light harvesting by the retinal pigments in the membrane.

  15. Buoyancy studies in natural communities of square gas-vacuolate archaea in saltern crystallizer ponds

    PubMed Central

    Oren, Aharon; Pri-El, Nuphar; Shapiro, Orr; Siboni, Nachshon

    2006-01-01

    Background Possession of gas vesicles is generally considered to be advantageous to halophilic archaea: the vesicles are assumed to enable the cells to float, and thus reach high oxygen concentrations at the surface of the brine. Results We studied the possible ecological advantage of gas vesicles in a dense community of flat square extremely halophilic archaea in the saltern crystallizer ponds of Eilat, Israel. We found that in this environment, the cells' content of gas vesicles was insufficient to provide positive buoyancy. Instead, sinking/floating velocities were too low to permit vertical redistribution. Conclusion The hypothesis that the gas vesicles enable the square archaea to float to the surface of the brines in which they live was not supported by experimental evidence. Presence of the vesicles, which are mainly located close to the cell periphery, may provide an advantage as they may aid the cells to position themselves parallel to the surface, thereby increasing the efficiency of light harvesting by the retinal pigments in the membrane. PMID:16613609

  16. Case study: design, operation, maintenance and water quality management of sustainable storm water ponds for roof runoff.

    PubMed

    Scholz, Miklas

    2004-12-01

    The purpose of this case study was to optimise design, operation and maintenance guidelines, and to assess the water treatment potential of a storm water pond system after 15 months of operation. The system was based on a combined silt trap, attenuation pond and vegetated infiltration basin. This combination was used as the basis for construction of a roof water runoff system from a single domestic property. United Kingdom Building Research Establishment and Construction Industry Research and Information Association, and German Association for Water, Wastewater and Waste design guidelines were tested. These design guidelines failed because they did not consider local conditions. The infiltration function for the infiltration basin was logarithmic. Algal control techniques were successfully applied, and treatment of rainwater runoff from roofs was found to be largely unnecessary for recycling (e.g., watering plants). However, seasonal and diurnal variations of biochemical oxygen demand, dissolved oxygen and pH were recorded.

  17. Dynamic Testing and Numerical Correlation Studies For Folsom Dam

    DTIC Science & Technology

    2005-09-01

    report prepared with support from the National Research Council of the United States reviewed the state of practice on seismic design and evaluation of...excitations. This report describes a research study conducted by the U.S. Army Engineer Research and Development Center consisting of a series of field...Forced Vibration Tests .....................................................................................6 Overview

  18. 7. VIEW OF DAM 83, SHOWING DIVERSION GATES TO SOURIS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF DAM 83, SHOWING DIVERSION GATES TO SOURIS RIVER CHANNEL (LEFT) AND POND A (RIGHT) FROM THE WEST SIDE OF THE OUTLET CHANNEL, LOOKING SOUTHEAST (for view of the original diversion gate, see historic photograph, HAER No. ND-3-A-15) - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  19. Small dams need better management

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-03-01

    Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four states in Australia, and developed policy benchmarks and best practices for small-dam management. Small dams, often just several meters high and typically privately owned by individual farmers, have historically caused major damage when they fail. For instance, in China in 1975, 230,000 people died when two large dams failed because of the cumulative failure of 60 smaller upstream dams. In the United States, in 1977 the 8-meter-high Kelly Barnes Lake dam failed, killing 39 people. Many other small-dam failures around the world have resulted in casualties and severe ecological and economic damage.

  20. Salt tracer experiments in constructed wetland ponds with emergent vegetation: laboratory study on the formation of density layers and its influence on breakthrough curve analysis.

    PubMed

    Schmid, Bernhard H; Hengl, Michael A; Stephan, Ursula

    2004-04-01

    Constructed wetlands are a rapidly expanding and intensively studied wastewater treatment system. One of the main types in use is the free water surface (FWS) wetland or wetland pond. In studies on these ponds, salt tracer experiments are a convenient tool to determine travel time distributions, which are, in turn, related to hydraulic and sedimentation (trapping) as well as nutrient removal efficiencies. Typically, flows encountered in constructed wetland ponds are characterized by low Reynolds numbers, at times even within the laminar flow regime. In such conditions the injection of salt may cause strong density effects, thereby threatening the usefulness of the recorded breakthrough curves. The processes and mechanisms governing the formation of density stratification due to salt tracer injections into wetland ponds with emergent vegetation were studied in the laboratory. The results reported are expected to be useful in the planning of future field tracer experiments.

  1. CFD study to determine the optimal configuration of aerators in a full-scale waste stabilization pond.

    PubMed

    Alvarado, Andres; Vesvikar, Mehul; Cisneros, Juan F; Maere, Thomas; Goethals, Peter; Nopens, Ingmar

    2013-09-01

    Aerated lagoons (ALs) are important variants of the pond wastewater treatment technology that have not received much attention in the literature. The hydraulic behaviour of ALs and especially the Facultative aerated lagoons (FALs) is very complex since the aeration in these systems is designed for oxygen transfer but not necessarily to create complete mixing. In this work, the energy expenditure of the aerators was studied by means of a scenario analysis. 3D CFD models (one phase and multiphase) of a 3 ha FAL in a waste stabilization pond system in Cuenca (Ecuador) were built for different configurations of aerators. The thrust produced by the aerators was modelled by an external momentum source applied as velocity vectors into the pond fluid. The predictions of a single phase model were in satisfactory agreement with experimental results. Subsequently, a scenario analysis assessing several aeration schemes with different numbers of aerators in operation were tested with respect to velocity profiles and residence time distribution (RTD) curves. This analysis showed that the aeration scheme with all 10 aerators switched on produces a similar hydraulic behaviour compared to using only 6 or 8 aerators. The current operational schemes comprise of switching off some aerators during the peak hours of the day and operating all 10 aerators during night. This current practice could be economically replaced by continuously operating 4 or 6 aerators without significantly affecting the overall mixing. Furthermore, a continuous mixing regime minimises the sediment oxygen demand enhancing the oxygen levels in the pond. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Effects of pond draining on biodiversity and water quality of farm ponds.

    PubMed

    Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

    2013-12-01

    Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo.

  3. Preliminary characterizations study on three soil samples from the Idaho National Engineering Laboratory warm waste pond

    SciTech Connect

    Burchett, R.T.; Richardson, W.S.; Hay, S.

    1994-12-31

    Three soil samples (Soil 1,2,and 3) from the Warm Waste Pond (WWP) system at the Test Reactor Area (TRA) of the Idaho National Engineering Laboratory (INEL) were sent to the National Air and Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama, for soil characterization and analysis. Each sample was vigorously washed and separated by particle size using wet sieving and vertical-column hydroclassification. The resulting fractions were analyzed for radioactivity by gamma spectroscopy. The following conclusions are based on the results of these analyses: (1) The three samples examined are dissimilar in many characteristics examined in the study. (2) The optimal parameters for vigorously washing the soil samples are a washing time of 30 min 350 rpm using a liquid-to-solid ratio of 4/1 (volume of water/volume of soil). (3) The only size fraction from Soil 1 that is below the 690 picocuries per gram (pCi/g) cesium-137 Record of Division (ROD) criterion is the +25.4-mm(+1-in) fraction, which represents 17 percent of the total soil. (4) There is no size fraction from Soil 2 that is below the 690 pCi/g cesium-137 criterion. (5) At optimal conditions, at least 66 percent of Soil 3 can be recovered with a cesium-137 activity level below the 690 pCi/g criterion. (6) For Soil 3, lowering the liquid-to-solid ratio from 4/1 to 2/1 during vigorous washing produces a higher weight-percent recovery of soil below the 690 pCi/g criterion. At a liquid-to-solid ratio of 2/1, 76 percent of the soil can be recovered with a concentration below the removal criterion, indicating that attrition followed by particle-size separation represents a potential method for remediation.

  4. Experimental Study on Cracking, Reinforcement, and Overall Stability of the Xiaowan Super-High Arch Dam

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Zhou, Weiyuan; Liu, Hongyuan

    2015-03-01

    The Xiaowan super-high arch dam has faced challenging construction problems. Here, we provide a scientifically-based reference for applying geomechanical model testing to support the nonlinear design of super-high arch dams. We applied experimental similarity theory and techniques. Based on four 3D geomechanical model tests, the dam stress characteristics, deformation distribution, and the safety factors of the dam foundation were identified and compared. We also analyzed cracking characteristics of the up- and downstream dam surfaces and induced joints in the dam heel, the rock mass failure process of the dam-foundation interface, and the abutments. We propose foundation reinforcement measures for weak rock masses, alteration zones, and other faults in the abutments based on the 3D and plane tests each at a different elevation. The results show that all dam deformations remained normal with no yielding or tensile cracking under a normal water load. The reinforced rock mass increased the crack initial safety in the dam heel and toe by ~20 %. The minimum crack initial safety factor ( K 1) of the dam heel was 1.4. The induced joint in the dam heel contributed to a reduction in tensile stress at the upstream dam heel, improving K 1. Compared with similar projects following reinforcement measures, the abutment stiffness and overall stability of the Xiaowan arch dam satisfy operational requirements. Four years of monitoring operations show that key areas near the dam remained normal and the dam foundation is functioning well. Our results may also be applicable to the design and construction of similar projects worldwide.

  5. Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams)

    PubMed Central

    Othman, Faridah; Taghieh, Mahmood

    2016-01-01

    Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam’s location (Series and parallel), conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands. PMID:27248152

  6. 106. DAM EARTH DIKE SUBMERSIBLE DAMS & DIKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    106. DAM - EARTH DIKE - SUBMERSIBLE DAMS & DIKE CONN. AT MOVABLE DAM (ML-8-52/2-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  7. Intercomparison of global river discharge simulations focusing on dam operation—multiple models analysis in two case-study river basins, Missouri-Mississippi and Green-Colorado

    NASA Astrophysics Data System (ADS)

    Masaki, Yoshimitsu; Hanasaki, Naota; Biemans, Hester; Müller Schmied, Hannes; Tang, Qiuhong; Wada, Yoshihide; Gosling, Simon N.; Takahashi, Kiyoshi; Hijioka, Yasuaki

    2017-05-01

    We performed an intercomparison of river discharge regulated by dams under four meteorological forcings among five global hydrological models for a historical period by simulation. This is the first global multimodel intercomparison study on dam-regulated river flow. Although the simulations were conducted globally, the Missouri-Mississippi and Green-Colorado Rivers were chosen as case-study sites in this study. The hydrological models incorporate generic schemes of dam operation, not specific to a certain dam. We examined river discharge on a longitudinal section of river channels to investigate the effects of dams on simulated discharge, especially at the seasonal time scale. We found that the magnitude of dam regulation differed considerably among the hydrological models. The difference was attributable not only to dam operation schemes but also to the magnitude of simulated river discharge flowing into dams. That is, although a similar algorithm of dam operation schemes was incorporated in different hydrological models, the magnitude of dam regulation substantially differed among the models. Intermodel discrepancies tended to decrease toward the lower reaches of these river basins, which means model dependence is less significant toward lower reaches. These case-study results imply that, intermodel comparisons of river discharge should be made at different locations along the river's course to critically examine the performance of hydrological models because the performance can vary with the locations.

  8. National Program for Inspection of Non-Federal Dams, Black Brook Dam (MA 01057), Connecticut River Basin, Blandford, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1980-03-01

    has been in operation since that time. (i) Normal Operation Procedure The Black Brook Dam is normally self regulating with the only controlled outlet...made from originals provided by the Soil Conserva- tion Service. 2.3 Operational Data 1 The dam is self regulating for flood control purposes, and no...operational procedures are available for this dam. The dam is normally self regulating for flood control purposes. The sluice gate on the pond drain is

  9. The geomorphic influences of beaver dams and failures of beaver dams

    NASA Astrophysics Data System (ADS)

    Butler, David R.; Malanson, George P.

    2005-10-01

    Uncounted millions of beaver ponds and dams existed in North America prior to European contact and colonization. These ponds acted as sediment traps that contained tens to hundreds of billions of cubic meters of sediment that would otherwise have passed through the fluvial system. Removal of beavers by overtrapping in the 16th-19th centuries severely reduced their number and the number of ponds and dams. Dam removal altered the fluvial landscape of North America, inducing sediment evacuation and entrenchment in concert with widespread reduction in the wetlands environments. Partial recovery of beaver populations in the 20th century has allowed reoccupation of the entirety of the pre-contact range, but at densities of only one-tenth the numbers. Nevertheless, modern beaver ponds also trap large volumes of sediment in the high hundred millions to low billions of cubic meters range. Failure of beaver dams is a more common phenomenon than often assumed in the literature. During the past 20 years, numerous cases of dam failure have been documented that resulted in outburst floods. These floods have been responsible for 13 deaths and numerous injuries, including significant impacts on railway lines.

  10. Resurgent beaver ponds in the northeastern United States: implications for greenhouse gas emissions.

    PubMed

    Lazar, Julia G; Addy, Kelly; Welsh, Molly K; Gold, Arthur J; Groffman, Peter M

    2014-11-01

    Beaver ponds, a wetland type of increasing density in the northeastern United States, vary spatially and temporally, creating high uncertainty in their impact to greenhouse gas (GHG) emissions. We used floating static gas chambers to assess diffusive fluxes of methane (CH), carbon dioxide (CO), and nitrous oxide (NO) from the air-water interface of three beaver ponds (0.05-8 ha) in Rhode Island from fall 2012 to summer 2013. Gas flux was based on linear changes of gas concentrations in chambers over 1 h. Our results show that these beaver ponds generated considerable CH and CO emissions. Methane flux (18-556 mg m d) showed no significant seasonal differences, but the shallowest pond generated significantly higher CH flux than the other ponds. Carbon dioxide flux (0.5-22.0 g m d) was not significantly different between sites, but it was significantly higher in the fall, possibly due to the degradation of fresh leaves. Nitrous oxide flux was low (0-2.4 mg m d). Overall, CH and CO comprised most of the global warming potential, 61 and 38%, respectively. The shallowness of the beaver ponds may have limited the time needed for CH oxidation to CO before CH escaped to the atmosphere. Beaver dams also increase the aerial extent of hydric soils, which may transform riparian areas from upland GHG sinks to wetland GHG sources thereby changing the net global warming potential. Further studies tracking the pattern and conditions of beaver pond creation and abandonment will be essential to understanding their role as GHG sources. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. The Legacy Ecosystem Management Framework: From Theory to Application in the Detention Pond Case Study

    SciTech Connect

    Coty, J; Stevenson, M; Vogt, K A

    2002-02-01

    The Detention Pond is a constructed and lined storm water treatment basin at Lawrence Livermore National Laboratory that serves multiple stakeholder objectives and programmatic goals. This paper examines the process and outcome involved in the development of a new management plan for the Detention Pond. The plan was created using a new ecosystem management tool, the Legacy Framework. This stakeholder-driven conceptual framework provides an interdisciplinary methodology for determining ecosystem health, appropriate management strategies, and sensitive indicators. The conceptual framework, the Detention Ponds project, and the use of the framework in the context of the project, are described and evaluated, and evaluative criteria for this and other ecosystem management frameworks are offered. The project benefited in several ways from use of the Legacy Framework, although refinements to the framework are suggested. The stakeholder process created a context and environment in which team members became receptive to using an ecosystem management approach to evaluate and support management alternatives previously not considered. This allowed for the unanimous agreement to pursue support from upper management and organizational funding to implement a progressive management strategy. The greatly improved stakeholder relations resulted in upper management support for the project.

  12. Salton Sea solar pond project

    NASA Technical Reports Server (NTRS)

    French, R. L.; Meitlis, I.

    1980-01-01

    The feasibility of constructing salt gradient solar ponds within the Salton Sea is being studied. These ponds would serve a dual purpose: (1) become a depository for unwanted salt and (2) supply thermal energy for driving turbine electric power systems. Under present circumstances, the rise in salinity is expected to eliminate fish life and create other unfavorable conditions. The proposed concept would have a power generation potential of 600 MWe.

  13. Phytoplankton, zooplankton, primary productivity and physico-chemical parameters of Par Pond and Pond B. Interim report, December 1983-May 1984

    SciTech Connect

    Chimney, M.J.; Cody, W.R.

    1985-04-01

    This report summarizes phytoplankton, zooplankton, primary productivity and physico-chemical parameter data from Par Pond and Pond B during the first six months of a study initiated in December 1983 and scheduled to continue through June 1985. A total of 195 phytoplankton taxa from Par Pond and 105 taxa from pond B were recorded during this study. A total of 89 zooplankton taxa from Par Pond and 58 taxa from Pond B were identified during this study.

  14. Biogeochemical ecology of aquaculture ponds

    SciTech Connect

    Weisburd, R.S.J.

    1988-01-01

    Two methods to determine rates of organic matter production and consumption were applied in shrimp aquaculture ponds. Several questions were posed: can net rates of organic matter production and consumption be determined accurately through application of dissolved inorganic carbon (DIC) mass balance in a pond with high advective through-put Are organically loaded aquaculture ponds autotrophic How do rates of organic production vary temporally Are there diurnal changes in respiration rates Four marine ponds in Hawaii have been evaluated for a 53 day period through the use of geochemical mass balances. All fluxes of DIC into and out of the ponds were considered. DIC was calculated from hourly pH measurements and weekly alkalinity measurements. Average uptake of DIC from the pond water, equivalent to net community production, revealed net autotrophy in all cases. Hourly and longer period variations in organic matter production rates were examined. The daily cycle dominated the variation in rates of net community production. Maximal rates of net community production were maintained for four to six hours starting in mid-morning. Respiration rates decreased rapidly during the night in two of the ponds and remained essentially constant in the others. A similar pattern of decreasing respiration at night was seen in freshwater shrimp ponds which were studied with incubations. A new method involving isotope dilution of {sup 14}C-labeled DIC was used to measure respiration rates in light and dark bottles. This method is an inexpensive and convenient procedure which should also be useful in other environments. The incubations demonstrated that plankton respiration rates peak at or soon after solar noon and vary over the course of the day by about a factor of two.

  15. A study of possible ground-motion amplification at the Coyote Lake Dam, California

    USGS Publications Warehouse

    Boore, D.M.; Graizer, V.M.; Tinsley, J.C.; Shakal, A.F.

    2004-01-01

    The abutment site at the Coyote Lake Dam recorded an unusually large peak acceleration of 1.29g during the 1984 Morgan Hill earthquake. Following this earthquake another strong-motion station was installed about 700 m downstream from the abutment station. We study all events (seven) recorded on these stations, using ratios of peak accelerations, spectral ratios, and particle motion polarization (using holograms) to investigate the relative ground motion at the two sites. We find that in all but one case the motion at the abutment site is larger than the downstream site over a broad frequency band. The polarizations are similar for the two sites for a given event, but can vary from one event to another. This suggests that the dam itself is not strongly influencing the records. Although we can be sure that the relative motion is usually larger at the abutment site, we cannot conclude that there is anomalous site amplification at the abutment site. The downstream site could have lower-than-usual near-surface amplifications. On the other hand, the geology near the abutment site is extremely complex and includes fault slivers, with rapid lateral changes in materials and presumably seismic velocities. For this reason alone, the abutment site should not be considered a normal free-field site.

  16. Synthesis of Sensor Fish Data for Assessment of Fish Passage Conditions at Turbines, Spillways, and Bypass Facilities – Phase 1: The Dalles Dam Spillway Case Study

    SciTech Connect

    Deng, Zhiqun; Serkowski, John A.; Fu, Tao; Carlson, Thomas J.; Richmond, Marshall C.

    2007-12-31

    This report summarizes the characterization of spillway passage conditions at The Dalles Dam in 2006 and the effort to complete a comprehensive database for data sets from The Dalles Dam spillway Sensor Fish and balloon-tagged live fish experiments. Through The Dalles Dam spillway case study, Pacific Northwest National Laboratory (PNNL) researchers evaluated the database as an efficient means for accessing and retrieving system-wide data for the U.S Army Corps of Engineers (USACE).

  17. Geo-environmental Study to Identify the Affecting Factors on Dohuk's Dam and the city (Northren Iraq) by Use Remote Sensing Techniques

    NASA Astrophysics Data System (ADS)

    Hamdon, Alaa

    2010-05-01

    The Dohuk's dam is one of the most important Aggregated dams in Iraq, located about 1 km from Dohuk city in northern Iraq, So; this vital project provides Dohuk city by water while the city formerly dependent on wells water prior to the establishing of the dam, and this is one of the main reasons for land-use expansion in Dohuk city and its vicinity,which is meant that the Dohuk's dam safety factor ,it is the key of the city safety factor .This dam has initiated the establishment of the dam in 1980 and was established in 1988, and it's capacity is 47.5 million cubic meters. This study aims to analyze the morphometric or geometric properties and the environmental factors at drainage systems and drainage network for Dohuk area's drainage basins (which recharges water of Dohuk Dam's Lake and it is accumulated by rainfall and spring water) scientifically and geometrically. Study of the geology of construction area of the dam Structuraly and tectonically. Satellite image, topographic maps and aerial photographs used in this study for merging its results together and preparing a drainage basin's maps and a geologic interpretation map for the study area to recognize the important geologic impact on the river which comes out from dam lake, also some of the field work investigation has been depended in this study. As a final result from morphometric analysis of drainage basins, tectonic analysis and geological investigations for study area, found as the following: 1 - Determining the amount of the accumulated sediments on the dam body, which has been carried by the collected rain-full water from the drainage basins, snow and spring water (the resources of Dam Lake). Study of the impact of these deposits on dam stability and evaluate the risk of these deposits on dam body and on its safety. 2 - Identification of geological features, which are that threaten the safety of the river of city which concern the only resource for the city and stability of dam body and its related

  18. Application of the contingent valuation method in a developing country: a case study of the Yusufeli dam in northeast Turkey.

    PubMed

    Alp, Emre; Yetiş, Ulkü

    2010-01-01

    Hydroelectric power plants and dams often play an important role in developing countries in terms of their contribution to economy. In accordance with the energy policies of Turkish Republic, Yusufeli Dam and Hydroelectric Power Plant in Northeastern Turkey have been initiated. In this study, the Contingent Valuation Method (CVM) was conducted in Yusufeli Village to determine the environmental costs of the Yusufeli Project. The purpose is to assess the willingness to pay (WTP) of Yusufeli Village residents for restoration of the environmental impacts of the dam project and also to investigate the underlying economic, psychological, and social motivations for WTP. WTP was calculated as US$761 per person which can further be used in the cost-benefit analysis. The results from the study suggest that application of the CVM in rural and urban areas located in the same region can show differences.

  19. A preliminary observation on the pond culture of European eel, Anguilla anguilla (Linnaeus, 1758) in Egypt: recommendations for future studies.

    PubMed

    El-Shebly, Abdalla A; El-kady, Mohamed A H; Hossain, M Yeamin

    2007-04-01

    An experiment was conducted to assess the potential of the European eel, Anguilla anguilla for earthen pond aquaculture without supplementary feeding at Lake Manzala, Egypt. Juvenile A. anguilla of mean length 11.7 cm and 2.4 g weight were stocked in earthen ponds measuring 3 feddans (about 12,600 m2) and 1 m deep. Stocking was done in May 2003 at a rate of 5000 fish feddan(-1) in a polyculture system including tilapia and mullets and fed mainly on natural occurring prey (natural spawned tilapia) and small shrimp. The eels were culture for a period of 2 years, May 2003 to April 2005. Sampling for growth and survival were evaluated yearly. At the end of the culture period, the gross weight of the harvested eels was measured and the net pond production calculated by the difference between weight stocked and weight harvested. Temperature varied from 11.5 to 28.2 degrees C and 12.2 to 29.3 degrees C; P(H), 7.3 to 8.9 and 7.5 to 8.8; Dissolved Oxygen (DO), 5.2 to 9.8 mg L(-1) and 4.1 to 8.3 mg L(-1); and Salinity, 2.5 to 5.5 psu and 3.0 to 6.8 psu for first year and second year, respectively. At the end of the culture period, A. anguilla attained average weight of 121.4 g fish(-1) at the end of the first year and a weight range of 152.5 to 430 g fish(-1) with an average of 280.36 g fish(-1) at the end of the second year. Survival rate ranged from 91% during the first year to 100% during the second year. Net eel production was 540.18 kg feddan(-1) at the end of the first year and 723.36 kg feddan(-1) at the end of the second year. Daily increments in weight per fish were 0.33 and 0.44 for first and second year, respectively. This experiment demonstrated the possibility of cultivation of eels as well as the higher growth rate in earthen ponds. The aquaculture strategy of eel with high stocking densities through low cost artificial feeds are recommended in future studies.

  20. Classification of the alterations of beaver dams to headwater streams in northeastern Connecticut, U.S.A.

    NASA Astrophysics Data System (ADS)

    Burchsted, Denise; Daniels, Melinda D.

    2014-01-01

    Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the impact of beaver dams at larger scales, this study examines channel shape and sediment distribution in thirty river reaches in northeastern Connecticut, U.S.A. The study reaches fall within the broader categories of impounded and free-flowing segments, leaving a third segment class of beaver meadows requiring additional study. Each of the study reaches were classified at the reach scale as free-flowing, valley-wide beaver pond, in-channel beaver pond, and downstream of beaver dam. The bankfull channel width to depth ratios and channel widths normalized by watershed area vary significantly across the study reach classes. Additionally, reaches modified by beaver dams have finer sediment distributions. This paper provides the first quantitative geomorphic descriptions of the in-channel beaver pond and reaches downstream of beaver dams. Given the different channel shapes and sediment distributions, we infer that geomorphic processes are longitudinally decoupled by these frequent barriers that control local base level. These barriers generate heterogeneity within a river network by greatly increasing the range of channel morphology and by generating patches controlled by different processes. Therefore, in spite of the small size of individual beaver dams, the cumulative effect of multiple dams has the potential to modify processes at larger spatial scales. To improve assessment of the

  1. Purification of Solar Ponds

    NASA Technical Reports Server (NTRS)

    Carpenter, S.

    1985-01-01

    Flocculatory agents added to solar saltponds remove turbidity to increase solar-energy collection efficiency. Flocculating agent or bacteriocide used to remove micro-organisms sprayed onto pond from airplane and allowed to settle to bottom of pond.

  2. Purification of Solar Ponds

    NASA Technical Reports Server (NTRS)

    Carpenter, S.

    1985-01-01

    Flocculatory agents added to solar saltponds remove turbidity to increase solar-energy collection efficiency. Flocculating agent or bacteriocide used to remove micro-organisms sprayed onto pond from airplane and allowed to settle to bottom of pond.

  3. Review of SERI solar pond work

    NASA Astrophysics Data System (ADS)

    Zangrando, F.; Johnson, D. H.

    1985-07-01

    This report provides documentation of SERI's solar pond research effort, which began in 1979. The SERI staff analyzed solar pond topics from modeling and feasibility studies to laboratory experiments on physical properties and hydrodynamical stability. The SERI's perspective on the maturity of this solar technology is described, including the technical state-of-the-art of salt-gradient solar ponds, state of knowledge of pond design, estimated cost ranges for various locations and applications, and perceived barriers to commercial development. Recommendations for future work are also presented. The SERI research and development on solar ponds is described, emphasizing analytical and experimental tools developed at SERI. All AERI and subcontract reports dealing with solar ponds or related system components are summarized, and a bibliography is provided.

  4. Diagnostic x-ray exposure and lens opacities: the Beaver Dam Eye Study.

    PubMed Central

    Klein, B E; Klein, R; Linton, K L; Franke, T

    1993-01-01

    The Beaver Dam Eye Study is a population-based study of common age-related eye diseases. During the standardized medical history, the 4926 subjects were asked whether they had ever had a chest x-ray, computerized axial tomography (CAT) scan of the head, other x-rays of the head, x-rays of the abdomen, or other diagnostic x-rays. The eye examination included photographs of the lenses of the eyes, which were subsequently graded according to protocol. Nuclear sclerosis and posterior subcapsular opacity were significantly associated with CAT scans. If these relationships are causal, it would highlight the importance of minimizing such exposure to the lens of the eye. PMID:8460743

  5. Waste Stabilization Ponds.

    ERIC Educational Resources Information Center

    Koundakjian, Philip

    This self-paced course contains reading assignments from a waste stabilization ponds operating manual, supportive text, example problems, and review questions, and a final examination. The course covers calculation of pond surface area, pond volume, organic load, detention time, drawdown, storage capacity, efficiency, and discharge. In addition,…

  6. Lagoons and Oxidation Ponds.

    ERIC Educational Resources Information Center

    O'Brien, W. J.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)

  7. Lagoons and Oxidation Ponds.

    ERIC Educational Resources Information Center

    O'Brien, W. J.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)

  8. Impacts of settlement, damming, and hydromanagement in two boreal lakes: A comparative paleolimnological study

    USGS Publications Warehouse

    Serieyssol, C.A.; Edlund, M.B.; Kallemeyn, L.W.

    2009-01-01

    Namakan Lake, located in shared border waters in northeastern Minnesota and northwestern Ontario, was subjected to several anthropogenic impacts including logging, damming, water-level manipulations, and perhaps climate change. We used paleolimnology to determine how these stressors impacted Namakan Lake in comparison to a control lake (Lac La Croix) that was not subject to damming and hydromanagement. One core was retrieved from each lake for 210Pb dating and analysis of loss-on-ignition and diatom composition. 210Pb-derived chronologies from the cores indicated that sediment accumulation increased after logging and damming in Namakan Lake; Lac La Croix showed no significant change. Loss-on-ignition analysis also showed an increase in concentration and accumulation of inorganic material after damming in Namakan Lake; again, minimal changes were observed in Lac La Croix. Diatom communities in both lakes displayed community shifts at the peak of logging. Simultaneous, post-1970s diatom community changes may reflect regional climate warming. Taxonomic richness in Namakan Lake decreased sharply after damming and the peak of logging, and was followed by a slow recovery to taxonomic richness similar to that prior to damming. Ecological variability among post-damming diatom communities, however, was greater in Namakan Lake than in Lac La Croix. A diatom calibration set was used to reconstruct historical conductivity and total phosphorus (TP). Lac La Croix showed little historical change in conductivity and TP. In contrast, conductivity increased for several decades in Namakan Lake after damming, possibly in relation to several large fires and flooding. Total phosphorus also increased in Namakan Lake after damming, with a possible decrease in the last decade to pre-damming TP levels. ?? Springer Science+Business Media B.V. 2008.

  9. A Study on the contribution of different food sources to shrimp growth in an intensive Fenneropenaeus chinensis pond

    NASA Astrophysics Data System (ADS)

    Su, Yuepeng; Ma, Shen; Tian, Xiangli; Dong, Shuanglin

    2008-11-01

    Stable isotope methods can be used to determine the food sources and prey items of aquatic organisms accurately and reliably. This study examined the relative contribution of artificial foods (the formulated feed and Artemia) and natural foods to shrimp growth in an intensive Fenneropenaeus chinensis pond by using carbon and nitrogen stable isotopes. The results showed that the nutrition utilization efficiency of the harvested shrimp was low, only 33.18% of feed nitrogen and 21.73% of feed carbon being converted to shrimp flesh. Our stable isotope results showed that the shrimp obtained nutrition for maximum growth from artificial foods, whose contribution was 93.5%, with the remaining attributed to the natural foods. However, there was 0.94 t harvested shrimp derived from natural foods (the rest of 13.56 t harvested shrimp derived from artificial foods) in 1ha intensive pond with a shrimp production of 14.50 t ha-1. Therefore, unit area shrimp production can be increased by increasing the contribution proportion of natural foods in intensive shrimp farming.

  10. Resource Conservation and Recovery Act corrective measures study: Area 6 decontamination pond facility, corrective action unit no. 92

    SciTech Connect

    1997-10-01

    Corrective Action Unit (CAU) No. 92, the Area 6 Decontamination Pond Facility (DPF), is an historic disposal unit located at the Nevada Test Site (NTS) in Nye County, Nevada (Figures 1 - 1, 1-2, and 1-3). The NTS is operated by the U.S. Department of Energy, Nevada Operations Office (DOE/NV), which has been required by the Nevada Division of Environmental Protection (NDEP) to characterize the DPF under the requirements of the Resource Conservation and Recovery Act (RCRA) Part A Permit (NDEP, 1995) for the NTS and Title 40 Code of Federal Regulations (CFR) Part 265 (1996c). The DPF is prioritized in the Federal Facility Agreement and Consent Order (FFACO, 1996) but is governed by the permit. The DPF was characterized through sampling events in 1994, 1996, and 1997. The results of these sampling events are contained in the Final Resource Conservation and Recovery Act Industrial Site Environmental Restoration Site Characterization Report, Area 6 Decontamination Pond Facility, Revision I (DOE/NV, 1997). This Corrective Measures Study (CMS) for the Area 6 DPF has been prepared for the DOE/NV`s Environmental Restoration Project. The CMS has been developed to support the preparation of a Closure Plan for the DPF. Because of the complexities of the contamination and regulatory issues associated with the DPF, DOE/NV determined a CMS would be beneficial to the evaluation and selection of a closure alternative.

  11. Intermediate pond sizes contain the highest density, richness, and diversity of pond-breeding amphibians.

    PubMed

    Semlitsch, Raymond D; Peterman, William E; Anderson, Thomas L; Drake, Dana L; Ousterhout, Brittany H

    2015-01-01

    We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes.

  12. Intermediate Pond Sizes Contain the Highest Density, Richness, and Diversity of Pond-Breeding Amphibians

    PubMed Central

    Semlitsch, Raymond D.; Peterman, William E.; Anderson, Thomas L.; Drake, Dana L.; Ousterhout, Brittany H.

    2015-01-01

    We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes. PMID:25906355

  13. Sedimentological downstream effects of dam failure and the role of sediment connectivity: a case study from the Bohemian Massif, Austria

    NASA Astrophysics Data System (ADS)

    Wurster, Maria-Theresia; Weigelhofer, Gabriele; Pichler-Scheder, Christian; Hein, Thomas; Pöppl, Ronald

    2017-04-01

    Sediment connectivity describes the potential for sediment transport through catchment systems, further defining locality and characteristics of sedimentation in river channels. Dams generally decrease sediment connectivity and act as temporary sediment sinks. When dams are removed these sediments are being reworked and released downstream. During dam restoration works along a small-sized stream in the Bohemian Massif of Austria in December 2015 a dam failure occurred which led to the entrainment of several tons of fine-grained reservoir sediments further entering and depositing in the downstream channel reaches, located in the Thayatal National Park. Aiming to remove these fine sediment deposits the National Park Authority decided to initiate a flushing event in April 2016. The main aim of the present study was to investigate the effects of dam failure-induced fine sediment release and reservoir flushing on downstream bed sediment characteristics by applying geomorphological mapping (incl. volumetric surveys) and sedimentological analyses (freeze-core sampling and granulometry), further discussing the role of in-channel sediment connectivity. The obtained results have shown that immediately after the dam failure event a total of ca. 18 m3 of fine-grained sediments have accumulated as in-channel sediment bars which were primarily formed in zones of low longitudinal connectivity (e.g. in the backwater areas of woody debris jams, or at slip-off bank locations). The flushing event has been shown to have caused remobilization and downstream translocation of these deposits, further reducing their total volume by approx. 60%. The results of the granulometric analyses of the freeze-core samples have revealed fine sediment accumulation and storage in the upper parts of the channel bed, having further increased after the flushing event. Additionally, effects on chemical conditions and invertebrate community have been observed. These observations clearly indicate a

  14. Analysis of Stream Channel Geometry Temporal and Spatial Evolution after Historic Dam Removal - two French case studies

    NASA Astrophysics Data System (ADS)

    Slawson, Deborah; Manière, Louis; Marchandeau, Florent

    2014-05-01

    IRSTEA, in partnership with the French Office national de l'eau et des milieux aquatiques (ONEMA), has begun a study of channel geomorphology in small streams where dams have been removed or breached between two and 200 years ago, without any subsequent restoration of the channel in the legacy sediments. A preliminary analysis of two sites in the Morvan, Burgundy, will be presented; a dam breached at the beginning of the 20th century and another in the last decade. Using ergodic reasoning, historical and recent upstream and downstream channel geometry is being used to predict the future temporal and spatial scales of channel physical habitat restoration. With the implementation of the European Water Framework Directive (WFD), dam removal has become a more frequently used method for restoring stream ecological continuity. In France, these obstacles are ubiquitous in medium and small streams and considerably reduce lateral and longitudinal connectivity. Improvement in the hydromorphologically controlled, physical habitat, particularly flow and sediment transport regimes, is often essential to improvement in stream biology. However, dam removal may cause long-term disturbances in flow and sediment transport regimes. In the absence of channel restoration measures in addition to dam removal, these disturbances may result in long-term negative impacts on fish, macroinvertebrate, and riparian plant physical habitat. These negative impacts may include channel incision and lowering of the water table, disconnection from floodplains, increased stream power and bed scouring, and increased sediment load from headcutting and bank erosion. Over time, these negative impacts may resolve themselves. However, the time frame necessary for reestablishing adequate physical habitat is not well-known. Some studies have indicated that many decades or longer may be required, depending on a variety of factors. Under the WFD, the REstoring rivers FOR effective catchment Management (REFORM

  15. An ecosystem service approach to support integrated pond management: a case study using Bayesian belief networks--highlighting opportunities and risks.

    PubMed

    Landuyt, Dries; Lemmens, Pieter; D'hondt, Rob; Broekx, Steven; Liekens, Inge; De Bie, Tom; Declerck, Steven A J; De Meester, Luc; Goethals, Peter L M

    2014-12-01

    Freshwater ponds deliver a broad range of ecosystem services (ESS). Taking into account this broad range of services to attain cost-effective ESS delivery is an important challenge facing integrated pond management. To assess the strengths and weaknesses of an ESS approach to support decisions in integrated pond management, we applied it on a small case study in Flanders, Belgium. A Bayesian belief network model was developed to assess ESS delivery under three alternative pond management scenarios: intensive fish farming (IFF), extensive fish farming (EFF) and nature conservation management (NCM). A probabilistic cost-benefit analysis was performed that includes both costs associated with pond management practices and benefits associated with ESS delivery. Whether or not a particular ESS is included in the analysis affects the identification of the most preferable management scenario by the model. Assessing the delivery of a more complete set of ecosystem services tends to shift the results away from intensive management to more biodiversity-oriented management scenarios. The proposed methodology illustrates the potential of Bayesian belief networks. BBNs facilitate knowledge integration and their modular nature encourages future model expansion to more encompassing sets of services. Yet, we also illustrate the key weaknesses of such exercises, being that the choice whether or not to include a particular ecosystem service may determine the suggested optimal management practice.

  16. Sport fishery potential of power plant cooling ponds: Final report

    SciTech Connect

    Heidinger, R.C.; Lewis, W.M.

    1986-10-01

    This research was undertaken to determine if cooling ponds could serve as habitat for several coolwater fish species and also to evaluate the potential use of cooling ponds as nursery areas for receiving waters. The work was conducted on two cooling ponds in northern Illinois. Walleye (Stizostedion vitreum), muskellunge (Esox masquinongy), striped bass (Morone saxatilis) fingerlings, and adult threadfin shad (Dorosoma petenense) were stocked into both cooling ponds. The hybrids between the striped bass and white bass (M. chrysops) had been previously stocked into Collins Pond. Smallmouth bass (Micropterus dolomieui) fingerlings and larval striped bass and walleye were stocked in Dresden Pond. Several sampling techniques including seining, electrofishing, and rotenoning were used to monitor growth and survival of stocked species. In addition, escapement of stocked and indigenous species was monitored at the Dresden Pond spillway. Walleye, muskellunge, striped bass and hybrid striped bass exhibited excellent growth in Collins Pond as did smallmouth bass in Dresden Pond. One of the primary differences between an open system (such as Dresden Pond) and a closed system (such as Collins Pond) is the potential that the open system has to serve as a fish nursery area for receiving waters. The stocking of ''coolwater'' species in a closed type system such as Collins Pond is an effective way to control and maintain selected sport species. Dresden Pond was not open to public fishing during this study, but Collins Pond developed an excellent sport fishery as a result of these stockings.

  17. An isotopic and chemical study of Lake Vanda and Don Juan Pond, Antarctica

    NASA Astrophysics Data System (ADS)

    Friedman, I.; Rafter, A.; Smith, G. I.

    Temperature measurements made in Lake Vanda and in the lake subbottom sediments show that the high temperatures in the lake are not due to geothermal heat flow, but are probably trapped solar energy. On the basis of Sr-87/86 ratios the salts in Lake Vanda can be derived by a mixture of 58% weathered rock plus 42% from sea water or precipitation. Loss of efflorescences high in sodium, potassium and magnesium by high winds can yield the salt compositions present in both Lake Vanda and Don Juan Pond. From isotopic data on deuterium, O-18, C-13, Sr-87/86, S-34 as well as from chemical data on Lake Vanda waters, interstitial brines contained in the subsurface sediment and C-14 dates a lake history is proposed.

  18. A subsurface study of the Denkman sandstone member, Norphlet Formation, hatters Pond field, Mobile County, Alabama

    SciTech Connect

    Young, L.M.; Anderson, E.G.; Baria, L.R. ); Higginbotham, R.S.

    1990-09-01

    Hatters Pond field is in east-central Mobile County in southwestern Alabama and it produces from both the Norphlet and Smackover formations. The structural trap involves salt movement along the west side of the Mobile Fault System that resulted in a faulted salt anticline. The Norphlet Formation of southwestern Alabama consists of red to gray siltstone and pinkish to gray sandstone with conglomerate layers. Three facies have been distinguished within the Norphlet Formation: a lower shale, a red siltstone sequence, and an upper quartzose unit. The thickness of the formation ranges from a feather edge to more than 800 ft (234.8 m) in southwestern Alabama. The Upper Jurassic Denkman Sandstone Member of the Norphlet Formation at Hatters Pond field is a medium- to fine-grained, well-sorted arkosic sandstone between the underlying Norphlet redbed lithofacies and the carbonates of the overlying Smackover Formation. Here, the Denkman Member can be subdivided into a massive upper unit and a low- to high-angle cross-stratified lower unit. The sandstones are quartz-rich with a high percentage of feldspars. The majority of the feldspar grains observed are potassium feldspar. Microcline is usually less altered when compared with other types of feldspar grains. The major types of feldspar replacement include illitization, hematitization, dolomitization, chloritization, calcitization, vacuolization, and anhydritization. Carbonate replacement of feldspars is very abundant, mostly by ferroan dolomite. Rock fragments are not abundant in the Denkman Member, although there is good evidence of a metamorphic/volcanic source area. The sandstones are cemented by dolomite, calcite, anhydrite, and quartz and feldspar overgrowths. The lower Denkman unit is slightly more porous than the upper Denkman unit. The pore-lining authigenic clay, illite, greatly reduces permeability and porosity in these sandstones.

  19. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  20. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  1. Measurements of radionuclide in Par Pond sediments with an underwater HPGe detector

    SciTech Connect

    Winn, W.G.

    1993-11-01

    Savannah River Site (SRS) effluent gamma emitting radionuclides in Par Pond sediment were examined in situ with an underwater HPGe detector prior to and following a 19 ft drawdown of the pond in 1991 to address dam repairs. These measurements provide a map of the {sup 137}Cs concentrations of the pond sediment, indicating that 9.4 {plus_minus} 1.5 Ci is exposed by the drawdown and that 46.6 {plus_minus} 7.2 Ci is the entire pond inventory. The highest individual {sup 137}Cs concentration was 25 {mu}Ci/m{sup 2} for the exposed sediment and 50 {mu}Ci/m{sup 2} for the entire pond. The results are consistent with parallel studies conducted by SREL, as well as historical data. Aside from {sup 137}Cs, the only other SRS-produced isotope observed was {sup 60}Co, with activity of only about 1% of that for {sup 137}Cs. This observation was also confirmed in grab samples of pond sediment and vegetation, which were returned to the laboratory for ultra-low-level gamma spectrometry analysis. A special effort was required to calibrate the underwater HPGe detector, where both measurements and calculational models were used. The effects of sediment depth profiles for density and {sup 137}Cs concentration were addressed in the calibration. Calibration factors for sediment surface concentrations ({mu}Ci/m{sup 2}/cpm) and sediment mass concentrations (pCi/kg/cpm) were obtained. In general, the {mu}Ci/m{sup 2}/cpm factor is recommended, as the pCi/kg/cpm factor depends on the depth location of the sediment of interest. However, a pCi/kg/cpm factor, which is dependent on the depth within the sediment is presented to address dose calculations that require it.

  2. Assessment of check-dam groundwater recharge with water-balance calculations

    NASA Astrophysics Data System (ADS)

    Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

    2017-04-01

    Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without

  3. Water Management Models in Practice: A Case Study of the Aswan High Dam

    NASA Astrophysics Data System (ADS)

    El-Ashry, M. T.; Alford, D. L.

    1984-04-01

    The stated purpose of this volume is the development and evaluation of operating policies for the Aswan High Dam and their relation to the development of water resources policy in Egypt. That objective is admirably fulfilled through discussions of water use in Egypt and the operation objectives of the High Dam, the behavior of the physical system and simulation of the reservoir, a realtime management model of the dam, management of water shortages and trade-offs between major uses, and coordinated operation of the dam with new upstream as well as downstream developments.The High Dam has been a source of controversy, particularly with regard to its environmental impacts. Its adverse effects include changes in the water table and attendant salt buildup in irrigated areas, excessive growth of aquatic plants below the dam, shoreline erosion, and increases in water-borne diseases such as schistosomiasis (bilharzia). The dam was intended to offset rapid population growth by increasing food supplies through the transformation of irrigated land in southern Egypt from seasonal to perennial cultivation and by providing water for the reclamation of desert land. Unfortunately, such benefits have been outstripped by the rapidly growing population, and water shortages will be experienced by the end of the century.

  4. Study on Optimal Grouting Timing for Controlling Uplift Deformation of a Super High Arch Dam

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Zhu, Xiaoxu; Li, Qingbin; Liu, Hongyuan; Yu, Yongjun

    2016-01-01

    A grouting model is developed for use during the grouting of the complex foundation of a super high arch dam. The purpose as to determine the optimal grouting timing and appropriate grouting pressure involved in controlling the uplift deformation of the dam. The model determines the optimal grouting time as the height of the arch dam increases with the concrete pouring, by checking the tensile stresses in the dam against standard specifications. The appropriate grouting pressures are given on the basis of the actual grouting pressures monitored during the upstream riverbed foundation grouting. An engineering procedure, applying the model, was then proposed and used during foundation grouting under the toe block of the Xiluodu super high-arch dam in south-western China. The quality of the foundation grouting was evaluated against the results from pressurized water permeability tests, acoustic wave velocity tests, elastic modulus tests and panoramic photographing of the rockmass on completion of the foundation grouting. The results indicated that the proposed grouting model can be applied to effectively reduce the uplift deformation and associated cracking risk for super high arch dams, and it can be concluded that the proposed engineering grouting procedure is a valuable tool for improving foundation grouting under the toe blocks of a super high arch dam.

  5. 78 FR 49735 - Intent To Prepare a Draft Environmental Impact Statement for Dam Safety Study, Lake Lewisville...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... Safety Study, Lake Lewisville Dam, Elm Fork Trinity River, Denton County, Texas AGENCY: Department of the... flood risk management, ] water supply, recreation and non-Federal hydropower. Top of conservation pool... rapid growth in the Lewisville, Grapevine, Dallas, Texas corridor along the Elm Fork and...

  6. 107. DAM EARTH DIKE SUBMERSIBLE DAMS PLANS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    107. DAM - EARTH DIKE - SUBMERSIBLE DAMS - PLANS & SECTIONS (ML-8-52/3-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  7. Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

    NASA Astrophysics Data System (ADS)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2015-08-01

    Beaver dams affect hydrologic processes, channel complexity, and stream temperature in part by inundating riparian areas, influencing groundwater-surface water interactions, and changing fluvial processes within stream systems. We explored the impacts of beaver dams on hydrologic and temperature regimes at different spatial and temporal scales within a mountain stream in northern Utah over a 3-year period spanning pre- and post-beaver colonization. Using continuous stream discharge, stream temperature, synoptic tracer experiments, and groundwater elevation measurements, we documented pre-beaver conditions in the first year of the study. In the second year, we captured the initial effects of three beaver dams, while the third year included the effects of ten dams. After beaver colonization, reach-scale (~ 750 m in length) discharge observations showed a shift from slightly losing to gaining. However, at the smaller sub-reach scale (ranging from 56 to 185 m in length), the discharge gains and losses increased in variability due to more complex flow pathways with beaver dams forcing overland flow, increasing surface and subsurface storage, and increasing groundwater elevations. At the reach scale, temperatures were found to increase by 0.38 °C (3.8 %), which in part is explained by a 230 % increase in mean reach residence time. At the smallest, beaver dam scale (including upstream ponded area, beaver dam structure, and immediate downstream section), there were notable increases in the thermal heterogeneity where warmer and cooler niches were created. Through the quantification of hydrologic and thermal changes at different spatial and temporal scales, we document increased variability during post-beaver colonization and highlight the need to understand the impacts of beaver dams on stream ecosystems and their potential role in stream restoration.

  8. 1000 dams down and counting

    USGS Publications Warehouse

    O'Connor, James E.; Duda, Jeff J.; Grant, Gordon E.

    2015-01-01

    Forty years ago, the demolition of large dams was mostly fiction, notably plotted in Edward Abbey's novel The Monkey Wrench Gang. Its 1975 publication roughly coincided with the end of large-dam construction in the United States. Since then, dams have been taken down in increasing numbers as they have filled with sediment, become unsafe or inefficient, or otherwise outlived their usefulness (1) (see the figure, panel A). Last year's removals of the 64-m-high Glines Canyon Dam and the 32-m-high Elwha Dam in northwestern Washington State were among the largest yet, releasing over 10 million cubic meters of stored sediment. Published studies conducted in conjunction with about 100 U.S. dam removals and at least 26 removals outside the United States are now providing detailed insights into how rivers respond (2, 3).

  9. Event-based stormwater management pond runoff temperature model

    NASA Astrophysics Data System (ADS)

    Sabouri, F.; Gharabaghi, B.; Sattar, A. M. A.; Thompson, A. M.

    2016-09-01

    Stormwater management wet ponds are generally very shallow and hence can significantly increase (about 5.4 °C on average in this study) runoff temperatures in summer months, which adversely affects receiving urban stream ecosystems. This study uses gene expression programming (GEP) and artificial neural networks (ANN) modeling techniques to advance our knowledge of the key factors governing thermal enrichment effects of stormwater ponds. The models developed in this study build upon and compliment the ANN model developed by Sabouri et al. (2013) that predicts the catchment event mean runoff temperature entering the pond as a function of event climatic and catchment characteristic parameters. The key factors that control pond outlet runoff temperature, include: (1) Upland Catchment Parameters (catchment drainage area and event mean runoff temperature inflow to the pond); (2) Climatic Parameters (rainfall depth, event mean air temperature, and pond initial water temperature); and (3) Pond Design Parameters (pond length-to-width ratio, pond surface area, pond average depth, and pond outlet depth). We used monitoring data for three summers from 2009 to 2011 in four stormwater management ponds, located in the cities of Guelph and Kitchener, Ontario, Canada to develop the models. The prediction uncertainties of the developed ANN and GEP models for the case study sites are around 0.4% and 1.7% of the median value. Sensitivity analysis of the trained models indicates that the thermal enrichment of the pond outlet runoff is inversely proportional to pond length-to-width ratio, pond outlet depth, and directly proportional to event runoff volume, event mean pond inflow runoff temperature, and pond initial water temperature.

  10. Treatment efficiency of a wet detention pond combined with filters of crushed concrete and sand: a Danish full-scale study of stormwater.

    PubMed

    Sønderup, Melanie J; Egemose, Sara; Bochdam, Timm; Flindt, Mogens R

    2015-12-01

    Traditional wet detention ponds and sand filters remove particles efficiently, whereas only a minor part of the dissolved and bioavailable load is removed. To improve the retention of dissolved substances, we tested crushed concrete as a filter material simultaneously with a traditional sand filter placed after an existing wet pond. The particulate fractions (particles, organic matter, phosphorus, and heavy metals) were removed efficiently in the pond and both filter materials, with the concrete filter often being best seen over a year. Dissolved heavy metals (lead (Pb), nickel (Ni), copper (Cu), chromium (Cr), and cadmium (Cd)) were largely retained, though a washout was observed from the pond (Ni and Cu), concrete filter (Cr), and sand filter (Ni) during the first month. The pond only retained total dissolved phosphorus (TDP) during summer. Crushed concrete and sand had a high (>70%) retention of TDP within the first months of operation, but the retention dropped in both filters due to a large oil load into the system (4 kg impermeable ha(-1) in 1 month). The poor retention might to some degree be due to mineralization processes turning particulate phosphorus (PP) into TDP. The massive oil load was retained efficiently (99.3%) in the pond and both filters, clearly illustrating that both filter materials were able to retain either oil or TDP. An additional pilot study showed that at residence times of 1 h, crushed concrete bound 90% TDP whereas sand only bound 22% TDP. Retention of TDP and PP decreased with shorter residence time in both materials, but fastest in sand.

  11. Erosion risk analysis by GIS in environmental impact assessments: a case study--Seyhan Köprü Dam construction.

    PubMed

    Sahin, S; Kurum, E

    2002-11-01

    Environmental Impact Assessment (EIA) is a systematically constructed procedure whereby environmental impacts caused by proposed projects are examined. Geographical Information Systems (GIS) are crucially efficient tools for impact assessment and their use is likely to dramatically increase in the near future. GIS have been applied to a wide range of different impact assessment projects and dams among them have been taken as the case work in this article. EIA Regulation in force in Turkey requires the analysis of steering natural processes that can be adversely affected by the proposed project, particularly in the section of the analysis of the areas with higher landscape value. At this point, the true potential value of GIS lies in its ability to analyze spatial data with accuracy. This study is an attempt to analyze by GIS the areas with higher landscape value in the impact assessment of dam constructions in the case of Seyhan-Köprü Hydroelectric Dam project proposal. A method needs to be defined before the overlapping step by GIS to analyze the areas with higher landscape value. In the case of Seyhan-Köprü Hydroelectric Dam project proposal of the present work, considering the geological conditions and the steep slopes of the area and the type of the project, the most important natural process is erosion. Therefore, the areas of higher erosion risk were considered as the Areas with Higher Landscape Value from the conservation demands points of view.

  12. Impact of beaver ponds on river discharge and sediment deposition along the Chevral River, Ardennes, Belgium

    NASA Astrophysics Data System (ADS)

    Nyssen, Jan; Frankl, Amaury; Pontzeele, Jolien; De Visscher, Maarten; Billi, Paolo

    2013-04-01

    With the recovery of the European beaver (Castor fiber) and their capacity to engineer fluvial landscapes, questions arise as to how they influence river discharge and sediment transport. The Chevral river (Ardennes, Belgium) contains two beaver dam sequences which appeared in 2004 and count now about 30 dams. Flow discharges and sediment fluxes were measured at the in- and outflow of each dam sequence. Volumes of sediment deposited behind the dams were measured. Between 2004 and 2011, peak flows were topped off, and the magnitude of extreme events decreased. 1710 m³ of sediment were deposited behind the beaver dams, with an average sediment thickness of 25 cm. The thickness of the sediment layer is related to the area of the beaver ponds. Along the stream, beaver pond sediment thickness displayed a sinusoidal deposition pattern, in which ponds with thick sediment layers were preceded by a series of ponds with thinner sediment layers. A downstream textural coarsening in the dam sequences was also observed, probably due to dam failures subsequent to surges. Differences in sediment flux between the in- and outflow at the beaver pond sequence were related to the river hydrograph, with deposition taking place during the rising limbs and slight erosion during the falling limbs. The seven-year-old sequences have filtered 190 tons of sediment out of the Chevral river, which is of the same order of magnitude as the 374 tons measured in pond deposits, with the difference between the values corresponding to beaver excavations (60 tons), inflow from small tributaries, and runoff from the valley flanks. Hydrogeomorphic effects of C. fiber and C. canadensis activity are similar in magnitude. The detailed analysis of changes to hydrology in beaver pond sequences confirms the potential of beavers to contribute to river and wetland restoration and catchment management.

  13. Hydropower and the environment: A case study at Glen Canyon Dam

    SciTech Connect

    Wegner, D.L.

    1995-12-31

    The management of hydroelectric resources in the Colorado River requires a balancing of hydrologic, social, natural and cultural resources. The resulting management often has to deal with inherently conflicting objectives, short and long-term goals, time frames and operational flexibility. Glen Canyon Dam, AZ, on the Colorado River, controls the release of water into the Grand Canyon. The dam has been under intense public scrutiny since it was completed in 1963. An Environmental Impact Statement evaluating the future operations and options for Glen Canyon Dam was initiated by the Department of the Interior in 1989 and completed in 1995. An Adaptive Management approach to future operational management has been developed as part of the Glen Canyon Dam Environmental Impact Statement process. Future operations at Glen Canyon Dam will take into consideration the need to balance water movement and hydroelectricity development with natural, recreation, Native American and cultural needs. Future management of rivers requires acknowledgement of the dynamic nature of ecosystems and the need to link scientific information into the decision-making process. Lessons learned and programs developed at Glen Canyon Dam may be applied to other river systems.

  14. Preliminary design of sedimentation ponds

    SciTech Connect

    Wilson, L.C.; Wayland, L.D.

    1982-12-01

    Almost one-hundred sedimentation ponds were conceptually designed for a large surface mining study are in northeast Texas. An approximate procedure was developed to economically estimate construction quantities in order to predict surface water control costs. This procedure utilized site-specific empirical relationships developed from detailed analyses on a representative number of proposed sedimentation ponds. Use of these equations provided earthwork volumes, and spillway pipe lengths. The procedure developed for this study is presented along with the results of a verification analysis.

  15. Clarifying the role of social comparison in the big-fish-little-pond effect (BFLPE): an integrative study.

    PubMed

    Huguet, Pascal; Dumas, Florence; Marsh, Herbert; Wheeler, Ladd; Seaton, Marjorie; Nezlek, John; Suls, Jerry; Régner, Isabelle

    2009-07-01

    It has been speculated that the big-fish-little-pond effect (BFLPE; the negative impact of highly selective academic settings on academic self-concept) is a consequence of invidious social comparisons experienced in higher ability schools. However, the direct role of such comparisons for the BFLPE has not heretofore been documented. The present study comprises the first evidence that the BFLPE (a) is eliminated after controlling for students' invidious comparisons with their class and (b) coexists with the assimilative and contrastive effects of upward social comparison choices on academic self-concept. These results increase understanding of the BFLPE and offer support for integrative approaches of social comparison (selective accessibility and interpretation comparison models) in a natural setting. They also lend support for the distinction between forced and deliberate social comparisons and the usefulness of distinguishing between absolute and relative comparison-level choice in self-assessment.

  16. A study of the natural biodegradation of two-phase olive mill solid waste during its storage in an evaporation pond.

    PubMed

    Borja, R; Sánchez, E; Raposo, F; Rincón, B; Jiménez, A M; Martín, A

    2006-01-01

    A study of the natural biodegradation of two-phase olive mill solid waste (OMSW) during its storage in an evaporation pond was carried out. This system is traditionally used as the final disposal of this waste or constitutes a previous stage before being processed by cogeneration or anaerobic digestion processes. A laboratory-scale pond with a total volume of 520 l was used. The experiment was carried out between December 2002 and August 2003 covering a total period of 269 days. During the experiment, the variations of temperature (outside and inside the pond), the effective volume of the OMSW in the pond, moisture content, total solids (TS), volatile solids (VS), the total chemical oxygen demand (TCOD), total volatile acids (TVA), pH and cumulative methane production as a function of the operation time were evaluated. The experimental results obtained showed that the characteristics of the two-phase OMSW in the pond were dependent on the time of operation and temperature. During the experiment, three periods were clearly observed and differentiated: (a) An initial period with a rapid reduction of moisture content and effective volume, with an increase of TS, VS and TCOD removals, a decrease of pH and an increase of TVA and methane production until day 21. (b) A second period of slow decrease of moisture content and effective volume, due to the decrease of the ambient temperature. This period took place between day 21 and days 120-150 of assay, and it was characterised by a slight change in the OMSW properties. (c) A third period where the characteristics of the waste in the pond changed considerably due to the increase of the temperature outside the pond. The methane gas production also showed an increase due to the increase of methanogenic activity with the increase of temperature. An empirical model to describe the changes of two-phase OMSW characteristics and methane production with the operation time was developed. The proposed model, based on the use of

  17. Performance study of a laboratory model shallow solar pond with and without single transparent glass cover for solar thermal energy conversion applications.

    PubMed

    Ganesh, S; Arumugam, S

    2016-12-01

    The thermal performance of a shallow solar pond with and without the single transparent glass cover has been investigated experimentally. This experiment has been performed during the summer season of 2014 under the operational condition for five different storage volumes of water upto a maximum of 10liter. The pond performance is investigated in terms of the rate of energy collected and its collection efficiency. A Low Density Polyethylene (LDPE) black sheet liner of 200μm thickness was laid on all the interior sides of the pond for solar energy absorption. A clear transparent PVC plastic sheet of 150μm thickness was laid over the water surface as evaporation suppressing membrane. Calibrated Copper constantan thermocouples were used to measure the temperatures of the system. A highest temperature of 81.5°C has been achieved for the stored volume of 2liter of water, when the pond was used with a single transparent glass cover of 5mm thickness. When the shallow solar pond was used without the transparent glass cover the system attained a maximum temperature of 62°C for the same stored volume of 2liter. A comparison between the two conditions of with and without the transparent glass cover, on the thermal performance of the SSP has been reported. A shallow solar pond system of the present type could be used us a source of warm water, of desired temperature, below 10°C which are required for the domestic and industrial utilities. The global warming is increased day by day; inorder to reduce global warming a typical method of small scale shallow solar pond has been used to absorb the radiation from the sun to convert it to useful heat energy by the source of water. The SSP is an eco friendly way to generate energy without polluting our environment and in an environment safety manner. Based on environmental safety this study has experimentally investigated the thermal performance of the shallow solar pond. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned.

  19. Effects of urbanization on three ponds in Middleton, Wisconsin

    USGS Publications Warehouse

    House, Leo B.

    1984-01-01

    A digital hydrologic model was used to simulate the effects of future residential development on pond inflow volumes and resulting water levels of three ponds in Middleton, Wisconsin. The model computed the daily water budget and the resulting water level for each pond. The results of the model calibration are presented in the report, along with the existing watershed hydrologic conditions and runoff volumes for the 1982 study period. Data was collected during 1982 to claibrate the model; the data included pond stage, ground-water levels, precipitation and other meteorological characteristics. In addition, water-quality samples were collected at each pond to characterize the water quality. Simulation of pond levels with the 1982 rainfall and fully developed watersheds did not result in stages greater than those observed in 1982. Simulation of pond levels with rainfall having a 20-year recurrence interval (1978) and hypothetical, fully developed watersheds resulted in maximum pond stages above those observed in 1982. Peak stage of Tiedeman 's Pond would increase by 2.77 feet, Stricker 's Pond by 3.91 feet, and Esser 's Pond by 1.44 feet. Simulation of pond levels with an estimated 100-year rainfall and hyopthetical, fully developed watersheds would result in peak stage increases of 5.30, 5.32, and 1.97 feet above the peak 1982 observed stages for Tiedeman's, Stricker's, and Esser 's Ponds, respectively. (USGS)

  20. Impact of dam construction on river banks evolution and sediment dynamics. A case study from the Po River (Italy).

    NASA Astrophysics Data System (ADS)

    Maselli, V.; Pellegrini, C.; Crose, L.; Del Bianco, F.; Mercorella, A.

    2014-12-01

    Rivers draining densely populated landscapes are extremely impacted by modern human engineering: armored beds, artificial levees and dams modified natural fluvial dynamics, and consequently, the evolution of alluvial plains, deltas and coastal environments. Dams, in particular, segmented the longitudinal continuity of the river and reduced (or even interrupted) the export of sediment toward the sea. Here we investigate the impact of the Isola Serafini dam on the upstream portion of the Po River (Italy) influenced by backwater, by using an integrated approach of aerial and satellite images, longitudinal cross-sections, grain size analysis, backscatter data and multibeam bathymetry. The analysis of aerial photographs, acquired every 10 yr since the dam construction in 1960, and of longitudinal cross-sections, allows understanding how the river adjusts its profile in response to the backwater and quantifying areas of net river banks erosion and deposition in meanders. The drowning of the reaches influenced by backwater reduced the progradation of point bars and promoted the deposition of fine grained sediments, as highlighted by grain size analysis on surficial sediment sampled across and along the river course. Calibrated back-scatter data with grain-size distributions of two selected meanders, under the backwater effect and beyond, show how sands are progressively replaced by fine-grained sediments in the meander belt and in the river axis, mainly reflecting the reduction of flow velocity, inferred also by river bed roughness. The understanding of river and sediment dynamics under the influence of backwater due to dam construction is useful when studying pristine systems in which natural backwater affects their evolution, as in the case of the formation of standing water bodies during the drowning of an incised valley.

  1. Fish community response to dam removal in a Maine coastal river tributary

    USGS Publications Warehouse

    Zydlewski, Joseph; Hogg, Robert S.; Coghlan, Stephen M.; Gardner, Cory

    2016-01-01

    Sedgeunkedunk Stream, a third-order tributary to the Penobscot River in Maine, historically has supported several anadromous fishes including Atlantic Salmon Salmo salar, Alewife Alosa pseudoharengus, and Sea Lamprey Petromyzon marinus. Two small dams constructed in the 1800s reduced or eliminated spawning runs entirely. In 2009, efforts to restore marine–freshwater connectivity in the system culminated in removal of the lowermost dam (Mill Dam) providing access to 4.7 km of lotic habitat and unimpeded passage into the lentic habitat of Fields Pond. In anticipation of these barrier removals, we initiated a modified before-after-control-impact study, and monitored stream fish assemblages in fixed treatment and reference sites. Electrofishing surveys were conducted twice yearly since 2007. Results indicated that density, biomass, and diversity of the fish assemblage increased at all treatment sites upstream of the 2009 dam removal. No distinct changes in these metrics occurred at reference sites. We documented recolonization and successful reproduction of Atlantic Salmon, Alewife, and Sea Lamprey in previously inaccessible upstream reaches. These results clearly demonstrate that dam removal has enhanced the fish assemblage by providing an undisrupted stream gradient linking a small headwater lake and tributary with a large coastal river, its estuary, and the Atlantic Ocean.

  2. National Program for Inspection of Non-Federal Dams. Bradley Hubbard Reservoir Dam (CT 00132), Quinnipiac River Basin, Meriden, Connecticut. Phase I Inspection Report.

    DTIC Science & Technology

    1980-09-01

    the Harbor Brook streambed. The maximum storage capacity with the pond level to the top of the dam is approximately 216 acre-feet of water . A...Division RICHARD DIE 0OO DE Water Control Branch Engineering Division ARAMAST HAITESLAN, CHAIMAN Geotechnical Enqineering Branch Engineering Division...The dam impounds 216 acre- feet of water with the reservoir level to the top of the dam, which at elevation 312.0, is 16.5 feet above the streambed of

  3. National Dam Inspection Program. Piney Run Dam (NDI-ID Number MD139), Chesapeake Bay Basin, Piney Run, Carroll County, Maryland. Phase I Inspection Report,

    DTIC Science & Technology

    1980-08-01

    I ,/ .110 / DAM PLAN. GEOLOGIC NVESTIGATION LAYOUT AND OUTLET CHANLa DETAILS PINEY RUN WATERSHED CARhLL cONTY. HARYLAND U . S . DEPARTMENT OF...34 hazard dam in accordance with U . S . Army Corps of Engineers dam safety critera. Based on the evaluation of available design information and visual...conditions and ascertain cause of intermittent ponded water. ~18 4 APPENDIX A VISUAL OBSERVATIONS CHECK LIST AND FIELD SKETCH L-J (n(L S - 0 U . V 00 m

  4. NASA Ames DEVELOP Interns Collaborate with the South Bay Salt Pond Restoration Project to Monitor and Study Restoration Efforts using NASA's Satellites

    NASA Technical Reports Server (NTRS)

    Newcomer, Michelle E.; Kuss, Amber Jean; Nguyen, Andrew; Schmidt, Cynthia L.

    2012-01-01

    In the past, natural tidal marshes in the south bay were segmented by levees and converted into ponds for use in salt production. In an effort to provide habitat for migratory birds and other native plants and animals, as well as to rebuild natural capital, the South Bay Salt Pond Restoration Project (SBSPRP) is focused on restoring a portion of the over 15,000 acres of wetlands in California's South San Francisco Bay. The process of restoration begins when a levee is breached; the bay water and sediment flow into the ponds and eventually restore natural tidal marshes. Since the spring of 2010 the NASA Ames Research Center (ARC) DEVELOP student internship program has collaborated with the South Bay Salt Pond Restoration Project (SBSPRP) to study the effects of these restoration efforts and to provide valuable information to assist in habitat management and ecological forecasting. All of the studies were based on remote sensing techniques -- NASA's area of expertise in the field of Earth Science, and used various analytical techniques such as predictive modeling, flora and fauna classification, and spectral detection, to name a few. Each study was conducted by a team of aspiring scientists as a part of the DEVELOP program at Ames.

  5. Water quality, phytoplankton and zooplankton of Par Pond and Pond B. Volume 2. Phytoplankton. Final report, January 1984-June 1985

    SciTech Connect

    Chimney, M.J.; Cody, W.R.; Starkel, W.M.

    1985-08-01

    This document reports on the Par Pond and Pond B phytoplankton community. The objectives of this study were to (1) characterize the biological communities and environmental conditions in Par Pond and Pond B; (2) assess the impact and significance of entrainment losses of plankton at the Par Pond pumphouse; (3) assess the impact of heated discharge on the biotic communities throughout the reservoir; and (4) help determine if Par Pond maintains an indigenous balanced biological community as defined in state and federal regulations. A total of 368 phytoplankton taxa, representing all the major taxonomic groups characteristic of North American freshwaters, were identified from Par Pond and Pond B during this study (73 Bacillariophyta, 166 Chlorophyta, 30 Chrysophyta, 5 Cryptophyta, 47 Cyanophyta, 18 Euglenophyta, 11 phytoflaggelates and 18 Pyrrophyta).

  6. Vermont lakes and ponds: a pilot recreation planning process

    Treesearch

    Daniel T. Malone; John J. Lindsay

    1992-01-01

    This report analyzes a pilot planning study conducted on two Vermont ponds by University of Vermont outdoor recreation planning students. It discusses the planning process used for these ponds and offers ways in which a statewide lake and pond planning process could be implemented.

  7. Studying and understanding the environmental impacts of the Three Gorges Dam in China

    NASA Astrophysics Data System (ADS)

    Schönbrodt-Stitt, Sarah; Stumpf, Felix; Schmidt, Karsten; Althaus, Paul; Bi, Renneng; Bieger, Katrin; Buzzo, Giovanni; Dumperth, Christian; Fohrer, Nicola; Rohn, Joachim; Strehmel, Alexander; Udelhoven, Thomas; Wei, Xiang; Zimmermann, Karsten; Scholten, Thomas

    2013-04-01

    network and early-warning system including local and regional authorities. Thus, the studies will contribute to a better understanding of the dimensions and dynamics of the ecological consequences of such large dam projects at the Yangtze River and worldwide.

  8. Methods for noninvasive bathymetric and velocity surveys for impoundment safety--A case study of Herrington Lake at Dix Dam near Burgin, Kentucky

    USGS Publications Warehouse

    Ruby, A. Thomas

    2012-01-01

    The U.S. Geological Survey (USGS) created bathymetric-contour and water-velocity vector maps for portions of Lake Herrington within 600 feet of the face of Dix Dam near Burgin, Kentucky. The mapping was in support of a study of noninvasive acoustic technology for assessing structural integrity of dams, both as a routine inspection tool or as an emergency tool during hydrologic events, such as high water or flooding. In April 2010, scientists from the USGS used a boat-mounted transducer and echo sounder to obtain bathymetric data to characterize lakebed relief and sediment distribution under a closed-intake condition. Also in April 2010, an acoustic Doppler current profiler was employed to measure water velocity and flow direction in the lake to locate velocities moving toward the dam face and, possibly, dam leakage. The bathymetric survey showed the present condition of fill in the reservoir since the dam was completed, as well as provided an outline of the lake floor. The velocity survey indicated no discernible flow pattern or direction within the study area; only one transect had shown a difference from the others that was noticeable. The noninvasive acoustic bathymetric and velocity surveys used during the case study showed promise in locating potential dam or intake maintenance areas. Additional case studies throughout the Nation are needed to more clearly define whether the methods for noninvasive bathymetric and velocity surveys for dam safety will be successful in a variety of settings.

  9. Influence of dams on sediment continuity: A study case of a natural metallic contamination.

    PubMed

    Frémion, Franck; Bordas, François; Mourier, Brice; Lenain, Jean-François; Kestens, Tim; Courtin-Nomade, Alexandra

    2016-03-15

    Sediments play an important role on the quality of aquatic ecosystems, notably in the reservoir areas where they can either be a sink or a source of contaminants, depending on the management and hydrological conditions. The physicochemical properties of 25 surface sediments samples of a reservoir catchment (Vaussaire, Cantal, France) were studied. Results show a strong influence of dam presence, notably on the grain size and organic matter (OM) contents. The concentrations of trace metals and metalloids (As, Cd, Cr, Cu, Ni, Pb and Zn) were also measured and compared with worldwide reservoir concentrations and international sediment quality guideline levels in order to assess the intensity of the metallic contamination. Cr and Ni are the trace elements presenting the significantly highest values at the catchment scale. Enrichment Factors (EF), calculated using both local and national backgrounds, show that metals have mainly a natural origin, explaining especially the Cr and Ni values, linked with the composition of parental rocks. Unexpectedly, all the observed metal concentrations are lower in the reservoir than upstream and downstream, which might be related to the high fresh OM inputs in the reservoir, diluting the global metallic contamination. Multivariate statistical analyses, carried out in order to identify the relationship between the studied metals and sediment characteristics, tend to support this hypothesis, confirming the unusually low influence of such poorly-degraded OM on trace element accumulation in the reservoir.

  10. Pilot study of using UAV to reveal spatial patterns of indicator bacteria concentrations in ponds and reservoirs used for irrigation

    USDA-ARS?s Scientific Manuscript database

    Determination of indicator bacteria concentrations in irrigation water recently became mandatory for farmers. These concentrations are known to have large spatial variability in ponds and reservoirs. This variability is partially attributed to affinity of indicator bacteria to algae accumulations. W...

  11. Surveying shrimp aquaculture pond activity using multitemporal VHSR satellite images - case study from the Perancak estuary, Bali, Indonesia.

    PubMed

    Gusmawati, Niken; Soulard, Benoît; Selmaoui-Folcher, Nazha; Proisy, Christophe; Mustafa, Akhmad; Le Gendre, Romain; Laugier, Thierry; Lemonnier, Hugues

    2017-04-04

    From the 1980's, Indonesian shrimp production has continuously increased through a large expansion of cultured areas and an intensification of the production. As consequences of diseases and environmental degradations linked to this development, there are currently 250,000ha of abandoned ponds in Indonesia. To implement effective procedure to undertake appropriate aquaculture ecosystem assessment and monitoring, an integrated indicator based on four criteria using very high spatial optical satellite images, has been developed to discriminate active from abandoned ponds. These criteria were: presence of water, aerator, feeding bridge and vegetation. This indicator has then been applied to the Perancak estuary, a production area in decline, to highlight the abandonment dynamic between 2001 and 2015. Two risk factors that could contribute to explain dynamics of abandonment were identified: climate conditions and pond locations within the estuary, suggesting that a spatial approach should be integrated in planning processes to operationalize pond rehabilitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Gradient zone erosion in seawater solar ponds

    SciTech Connect

    Shi, J.; Hart, R.A.; Kleis, S.J.; Bannerot, R.B.

    1995-11-01

    An experimental program has been conducted to examine the feasibility of using seawater solar ponds in mariculture operations along the Texas gulf coast to protect fish crops from the potentially lethal, cold temperatures experienced in outdoor ponds. Seawater solar ponds in the form of floating thermal refuge areas are proposed as a method for reducing the loss of heat from small sections of a pond. Gradient zone erosion under various ambient and operating conditions is examined. Comparisons with previous laboratory studies show a much lower entrainment rate in the natural environment. A simple (linear) correlation of entrainment rate with wind speed was found, for conditions which are typical of those encountered in mariculture pond operations.

  13. a Study on the Stability of Earth DAM Subjected to the Seismic Load

    NASA Astrophysics Data System (ADS)

    Qi, Jinghua; Che, Ailan; Ge, Xiurun

    For ensuring the earth dam's stability of Wangqingtuo reservoir when silt liquefaction happens during Tangshan earthquake, a large amount of laboratory soil tests and field measurements have been performed to obtain the mechanic properties of the soil and silt dynamic parameters. On the basis of the soil tests, the equivalent linear constitutive model is employed in the dynamic numerical simulation of the typical dam and the results indicate that the shear deformation is induced by the foundation liquefaction with the help of the geo-slope software. Moreover, the stability analysis is performed using the finite element elasto-plastic model that is considered the Mohr-Coulomb failure criteria to calculate the stability factor. The factors indicate the local instability would take place because of the shear action. At last, the measures are introduced to the designers for preventing the dam from the instability.

  14. Prediction of soil water erosion risk within GIS-case study of Beni Amrane Dam catchment (North of Algeria)

    NASA Astrophysics Data System (ADS)

    Touahir, S.; Khenter, K.; Remini, B.; Saad, H.

    2017-08-01

    Isser River is one of North Algeria’s major resources. It is vulnerable to water soil erosion because of favourable conjunctions of different geomorphological, hydro-climatic and lithologic factors. This case study has been carried out on the Beni Amrane dam Catchment, which is located in the bottom of Isser River, in North Algeria. The study involves a mapping of main factors of water erosion: rainfall erosivity, soil erodibility, slope and land use. Essentially a data mapping specification analysis shows, on each factor, how to identify the areas that are prone to water erosion. 04 classes of multifactorial vulnerability to water erosion have been identified: areas with low vulnerability (10 per cent); area with middle vulnerability (49 per cent); areas with high and very high vulnerability (38 per cent and 3 per cent). This could be a first guidance document for a rational use of land in the region and better secure the Beni Amrane dam against reservoir siltation.

  15. The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    USGS Publications Warehouse

    Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Smith, Lacy M.; Moskal, Stacy M.; De La Cruz, Susan E. W.; Yee, Julie L.; Takekawa, John Y.

    2014-01-01

    The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populations, the South Bay Salt Pond Restoration Project plans to create new islands within former salt ponds in South San Francisco Bay. In a series of studies, we investigated pond and individual island attributes that are most beneficial to nesting, foraging, and roosting waterbirds.

  16. Solar ponds: a selected bibliography

    SciTech Connect

    Not Available

    1981-11-01

    This bibliography contains citations on: regular solar ponds; shallow solar ponds; and patents. Certain references are specifically recommended. The data bases searched for the bibliography are listed. (LEW)

  17. Predation by northern pikeminnow on juvenile salmonids in The Dalles Dam tailrace: field, laboratory, and habitat modeling studies (FY2000)

    USGS Publications Warehouse

    Petersen, James H.; Barfoot, Craig A.; Sheer, Mindi B.

    2001-01-01

    Predation by resident fish is known to be a substantial cause of juvenile salmonid mortality, especially in dam tailraces and outfall locations. Conditions in The Dalles Dam tailrace are unique compared to other projects on the Columbia or Snake rivers, having a complex basin with a series of downriver islands where predators are known to reside. In May-June of 1999, northern pikeminnow and smallmouth bass were sampled in the tailrace of The Dalles Dam during periods immediately following the release of PIT-tagged juvenile salmonids for survival studies. Over twice as many smallmouth bass (N = 101) were collected as northern pikeminnow (N = 40), but none of the predators had PIT tags within their gut. A laboratory study was conducted to estimate the time required for PIT tags in juvenile salmonids to be evacuated from the gut of northern pikeminnow after consuming a tagged preyfish. Evacuation rate was sensitive to temperature, with median evacuation time being 21 h at 18 oC and 30 h at 14 oC. These results suggest that field studies to estimate predator population sizes, feeding rates, or predation on specific release groups would require considerably more effort than we allocated during 1999.

  18. Pond-aquifer interaction at South Pond of Lake Cochituate, Natick, Massachusetts

    USGS Publications Warehouse

    Friesz, Paul J.; Church, Peter E.

    2001-01-01

    A U.S. Army facility on a peninsula in South Pond of Lake Cochituate was designated a Superfund site by the U.S. Environmental Protection Agency in 1994 because contaminated ground water was detected at the facility, which is near the Natick Springvale public-supply wellfield. The interaction between South Pond and the underlying aquifer controls ground-water flow patterns near the pond and determines the source of water withdrawn from the wellfield.A map of the bathymetry and the thickness of fine-grained pond-bottom sediments was prepared on the basis of fathometer, ground-penetrating radar, and continuous seismic-reflection surveys. The geophysical data indicate that the bottom sediments are fine grained toward the middle of the pond but are coarse grained in shoreline areas. Natick Springvale wellfield, which consists of three active public-supply wells adjacent to South Pond, is 2,200 feet downgradient from the boundary of the Army facility. That part of South Pond between the Natick Springvale wellfield and the Army facility is 18 feet deep with at least 14 feet of fine-grained sediment beneath the pond-bottom. Water levels from the pond and underlying sediments indicate a downward vertical gradient and the potential for infiltration of pond water near the wellfield. Head differences between the pond and the wellfield ranged from 1.66 to 4.41 feet during this study. The velocity of downward flow from South Pond into the pond-bottom sediments, determined on the basis of temperature profiles measured over a diurnal cycle at two locations near the wellfield, was 0.5 and 1.0 feet per day. These downward velocities resulted in vertical hydraulic conductivities of 1.1 and 2.9 feet per day for the pond-bottom sediments.Naturally occurring stable isotopes of oxygen and hydrogen were used as tracers of pond water and ground water derived from recharge of precipitation, two potential sources of water to a well in a pond-aquifer setting. The isotopic composition of pond

  19. Flood prevention dams for arid regions at a micro-scale sub-catchment, case study: Tabuk, Saudi Arabia.

    PubMed

    Abushandi, Eyad

    2016-12-01

    Unexpected flash flooding is one of the periodic hydrological problems affecting the city of Tabuk in Saudi Arabia. The region has high potential for floods as it suffers high rainfall intensity in a short time and also has high urbanization rates and topographic complexity. Constructing flood prevention dams is one option to solve this problem. A cost-effective design requires a detailed feasibility study and analysis for the selection of suitable sites. The aim of this study was to develop a method for selecting a suitable site for flood protection dams in the Abu Saba'a district, the most affected part of the city of Tabuk during the flash flood in January 2013. Spatial analysis was applied using Landsat Thematic Mapper images and Shuttle Radar Topography Mission digital elevation model to select a site in the Abu Saba'a area. A simple model using ArcGIS was built including all suggested parameters. The results showed the best site for a dam was 2 km distance backfrom the area, where all parameter values matched. The results showed that the dynamic properties of land cover can affect site selection. It is therefore suggested that more field and hydrological data should be gathered for greater accuracy.

  20. Ground Penetration Radar (GPR) Studies in Kureyşler Dam Rescue Excavations, Kütahya, Turkey

    NASA Astrophysics Data System (ADS)

    Mutlu, S.; Tün, M.; Pekkan, E.; Ecevitoğlu, B.; Guney, Y.

    2016-12-01

    Kureyşler Dam Rescue Excavations shows up as an important archaeological study implemented in Kütahya. It provides valuable data on and deepens our understanding of the Inner Western Anatolian region alongside Seyitömer and Çiledir Mound Excavations. The rescue excavations were started with the aim of determining the cultural artefacts that would be flooded by Kureyşler Irrigation Dam. Rescue excavations in archaeology, mostly called salvage archaeology, is archaeological survey and excavation applied in areas revealed by some constructions. These works must be undertaken in the shortest possible time, unlike traditional survey and excavation. Use of ground penetrating radar (GPR) allows field archaeologists to quickly discover and map buried archaeological features. This study describes the use of GPR during a rescue archaeology campaign at the Kureyşler Irrigation Dam, in Kütahya (Turkey). Closely spaced GPR transects were collected in a grid-based approach, covering three different areas from the site, using GSSI Sir 3000 System, with antennae frequency of 400MHz. Ground penetrating radar data were evaluated with a few commercial software. According to the interpretation of geophysical data, we suggested some excavation sites. The ancient ruins were found in the suggested area quite successful.

  1. Big Fish in a Big Pond: a study of academic self concept in first year medical students

    PubMed Central

    2011-01-01

    Background Big-fish-little-pond effect (BFLPE) research has demonstrated that students in high-ability environments have lower academic self-concepts than equally able students in low-ability settings. Research has shown low academic self-concepts to be associated with negative educational outcomes. Social comparison processes have been implicated as fundamental to the BFLPE. Methods Twenty first-year students in an Australian medical school completed a survey that included academic self-concept and social comparison measures, before and after their first written assessments. Focus groups were also conducted with a separate group of students to explore students' perceptions of competence, the medical school environment, and social comparison processes. Results The quantitative study did not reveal any changes in academic self-concept or self-evaluation. The qualitative study suggested that the attributions that students used when discussing performance were those that have been demonstrated to negatively affect self-concept. Students reported that the environment was slightly competitive and they used social comparison to evaluate their performance. Conclusions Although the BFLPE was not evident in the quantitative study, results from the qualitative study suggest that the BFLPE might be operating In that students were using attributions that are associated with lower self-concepts, the environment was slightly competitive, and social comparisons were used for evaluation. PMID:21794166

  2. Forebay Computational Fluid Dynamics Modeling for The Dalles Dam to Support Behavior Guidance System Siting Studies

    SciTech Connect

    Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.; Johnson, Gary E.

    2005-03-10

    Computational fluid dynamics (CFD) models were developed to support the siting and design of a behavioral guidance system (BGS) structure in The Dalles Dam (TDA) forebay on the Columbia River. The work was conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District (CENWP). The CFD results were an invaluable tool for the analysis, both from a Regional and Agency perspective (for the fish passage evaluation) and a CENWP perspective (supporting the BGS design and location). The new CFD model (TDA forebay model) included the latest bathymetry (surveyed in 1999) and a detailed representation of the engineered structures (spillway, powerhouse main, fish, and service units). The TDA forebay model was designed and developed in a way that future studies could easily modify or, to a large extent, reuse large portions of the existing mesh. This study resulted in these key findings: (1) The TDA forebay model matched well with field-measured velocity data. (2) The TDA forebay model matched observations made at the 1:80 general physical model of the TDA forebay. (3) During the course of this study, the methodology typically used by CENWP to contour topographic data was shown to be inaccurate when applied to widely-spaced transect data. Contouring methodologies need to be revisited--especially before such things as modifying the bathymetry in the 1:80 general physical model are undertaken. Future alignments can be evaluated with the model staying largely intact. The next round of analysis will need to address fish passage demands and navigation concerns. CFD models can be used to identify the most promising locations and to provide quantified metrics for biological, hydraulic, and navigation criteria. The most promising locations should then be further evaluated in the 1:80 general physical model.

  3. Air demand estimation in bottom outlets with the particle finite element method. Susqueda Dam case study

    NASA Astrophysics Data System (ADS)

    Salazar, Fernando; San-Mauro, Javier; Celigueta, Miguel Ángel; Oñate, Eugenio

    2017-07-01

    Dam bottom outlets play a vital role in dam operation and safety, as they allow controlling the water surface elevation below the spillway level. For partial openings, water flows under the gate lip at high velocity and drags the air downstream of the gate, which may cause damages due to cavitation and vibration. The convenience of installing air vents in dam bottom outlets is well known by practitioners. The design of this element depends basically on the maximum air flow through the air vent, which in turn is a function of the specific geometry and the boundary conditions. The intrinsic features of this phenomenon makes it hard to analyse either on site or in full scaled experimental facilities. As a consequence, empirical formulas are frequently employed, which offer a conservative estimate of the maximum air flow. In this work, the particle finite element method was used to model the air-water interaction in Susqueda Dam bottom outlet, with different gate openings. Specific enhancements of the formulation were developed to consider air-water interaction. The results were analysed as compared to the conventional design criteria and to information gathered on site during the gate operation tests. This analysis suggests that numerical modelling with the PFEM can be helpful for the design of this kind of hydraulic works.

  4. Juvenile Radio-Tag Study: Lower Granite Dam, 1985 Annual Report.

    SciTech Connect

    Stuehrenberg, Lowell C.

    1986-06-01

    The concept of using mass releases of juvenile radio tags represents a new and potentially powerful research tool that could be effectively applied to juvenile salmonid passage problems at dams on the Columbia and Snake Rivers. A system of detector antennas, strategically located, would automatically detect and record individually tagged juvenile salmonids as they pass through the spillway, powerhouse, bypass system, or tailrace areas below the dam. Accurate measurements of spill effectiveness, fish guiding efficiency (FGE), collection efficiency (CE), spillway survival, powerhouse survival, and bypass survival would be possible without handling large numbers of unmarked fish. A prototype juvenile radio-tag system was developed and tested by the National Marine Fisheries Service (NMFS) and Bonneville Power Administration (BPA) at John Day Dam and at Lower Granite Dam. This report summarizes research to: (1) evaluate the effectiveness of the prototype juvenile radio-tag system in a field situation and (2) to test the basic assumptions inherent in using the juvenile radio tag as a research tool.

  5. Air demand estimation in bottom outlets with the particle finite element method - Susqueda Dam case study

    NASA Astrophysics Data System (ADS)

    Salazar, Fernando; San-Mauro, Javier; Celigueta, Miguel Ángel; Oñate, Eugenio

    2016-06-01

    Dam bottom outlets play a vital role in dam operation and safety, as they allow controlling the water surface elevation below the spillway level. For partial openings, water flows under the gate lip at high velocity and drags the air downstream of the gate, which may cause damages due to cavitation and vibration. The convenience of installing air vents in dam bottom outlets is well known by practitioners. The design of this element depends basically on the maximum air flow through the air vent, which in turn is a function of the specific geometry and the boundary conditions. The intrinsic features of this phenomenon makes it hard to analyse either on site or in full scaled experimental facilities. As a consequence, empirical formulas are frequently employed, which offer a conservative estimate of the maximum air flow. In this work, the particle finite element method was used to model the air-water interaction in Susqueda Dam bottom outlet, with different gate openings. Specific enhancements of the formulation were developed to consider air-water interaction. The results were analysed as compared to the conventional design criteria and to information gathered on site during the gate operation tests. This analysis suggests that numerical modelling with the PFEM can be helpful for the design of this kind of hydraulic works.

  6. Evaluation of Dam Decommissioning in an Ice-Affected River: Case Study

    DTIC Science & Technology

    2007-09-01

    Abdul-Mohsen 2005 and Kuby et al. 2005). Conyngham et al. (2006) provide an overview of the ecological and engi- neering aspects of dam decommissioning...2007) CRREL Ice Jam Database (http://www.crrel.usace.army.mil/ierd/ijdb/), accessed March 2007. Kuby , M.J., W.F. Fagan, C.S. ReVelle, W.L. Graf (2005

  7. Bulletins examine dam issues

    SciTech Connect

    Ervine, A.

    1994-12-31

    This month`s Tech Notes includes discussions of bulletins on upstream slope protection of embankment dams, dams and environmental geophysical impacts, rock materials for rockfill dams, and a scathing review of various hydro efforts accross the world.

  8. Olfactory impairment in an adult population: the Beaver Dam Offspring Study.

    PubMed

    Schubert, Carla R; Cruickshanks, Karen J; Fischer, Mary E; Huang, Guan-Hua; Klein, Barbara E K; Klein, Ronald; Pankow, James S; Nondahl, David M

    2012-05-01

    The objective of this study was to determine the prevalence of olfactory impairment and associated risk factors and the effects of olfactory impairment on dietary choices and quality of life. Odor identification was measured in 2838 participants aged 21-84 years (mean 49 years) in the Beaver Dam Offspring Study. The overall prevalence of olfactory impairment was 3.8%, increased with age (from 0.6% in those<35 years to 13.9% among those≥65 years) and was more common in men than women. In a multivariate model age (odds ratio [OR]=1.48, 95% confidence interval [CI]=1.33, 1.64 for every 5-year increase), nasal polyps or deviated septum (OR=2.69, 95% CI=1.62, 4.48), ankle-brachial index<0.9 (OR=3.62, 95% CI=1.45, 9.01), and smoking (women only) (OR=2.43, 95% CI=1.19, 4.98 ever smoked vs. never) were associated with an increased odds of olfactory impairment, whereas higher household income, ≥$50,000 versus <$50,000 per year, was associated with a decreased odds of olfactory impairment (OR=0.48, 95% CI=0.31, 0.73). Participants with olfactory impairment were less likely to report that food tasted as good as it used to, or that they experienced food flavors the same. There was no association between olfactory impairment and general health-related quality of life, depressive symptoms, or dietary choices. The prevalence of olfactory impairment was low in this largely middle-aged cohort, and some factors associated with olfactory impairment are potentially modifiable.

  9. Interim results from a study of the behavior of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March--August 2011

    USGS Publications Warehouse

    Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.

    2012-01-01

    The movements and dam passage of yearling juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. A total of 411 hatchery fish and 26 wild fish were tagged and released between March 7 and May 21, 2011. A series of 16 autonomous hydrophones placed throughout the reservoir were used to determine general fish movements over the life of the acoustic transmitter, which was expected to be 91 days. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back. The dam passage rate was 11.2 percent (95-percent confidence interval 7.8–14.6 percent) for hatchery fish and 15.4 percent (95-percent confidence interval -1.0–31.8 percent) for wild fish within 91 days from release. Most fish passage occurred at night. The median time from release to dam passage was 34.5 days for hatchery fish and 34.2 days for wild fish. A system of hydrophones near the dam outlet, a temperature control tower, was used to estimate positions of fish in three dimensions to enable detailed analyses of fish behavior near the tower. Analyses of these data indicate that hourly averaged depths of fish within a distance of 74 m from the upstream face of the tower ranged from 0.6 to 9.6 meters, with a median depth of 3.6 meters for hatchery fish and 3.4 meters for wild fish. Dam discharge rates and the diurnal period affected the rates of dam passage. Rates of dam passage were similar when the dam discharge rate was less than 1,200 cubic feet per second, but increased sharply at higher discharges. The rate of dam passage at night was 4.4–7.8 times greater than during the day, depending on the distance of fish from the dam. This report is an interim summary of data collected as of August 3, 2011, for planning purposes.

  10. Study on method and mechanism of deep well circulation for the growth control of Microcystis in aquaculture pond.

    PubMed

    Cong, Haibing; Sun, Feng; Wu, Jun; Zhou, Yue; Yan, Qi; Ren, Ao; Xu, Hu

    2017-06-01

    In order to control the growth of Microcystis in aquaculture ponds and reduce its adverse effect on water quality and aquaculture, a production-scale experiment of deep well circulation treatment was carried out in an aquaculture pond with water surface area of 63,000 m(2) and water depth of 1.6-2.0 m. Compared with the control pond, the experiment pond had better water quality as indicated by 64.2% reduction in chlorophyll a, and 81.1% reduction in algal cells. The chemical oxygen demand, total nitrogen, and total phosphorus concentration were reduced by 55.1%, 57.5%, and 50.8%, respectively. The treatment efficiency is mainly due to the growth control of Microcystis (i.e. cell reduction of 96.4%). The gas vesicles collapsing because of the water pressure was suggested to be the mechanism for Microcystis suppression by the deep well circulation treatment. The Microcystis lost its buoyancy after gas vesicles collapsed and it settled to the bottom of the aquaculture pond. As a result, the algae reproduction was suppressed because algae could only grow in the area with enough sunlight (i.e. water depth less than 1 m).

  11. Melt Pond Optics

    NASA Image and Video Library

    2017-09-27

    On July 6, 2011, Don Perovich, of Cold Regions Research and Engineering Laboratory, used a spectroradiometer to measure the amount of sunlight reflected from the surface of ice and melt ponds in the Chukchi Sea. The ICESCAPE mission, or "Impacts of Climate on Ecosystems and Chemistry of the Arctic Pacific Environment," is a NASA shipborne investigation to study how changing conditions in the Arctic affect the ocean's chemistry and ecosystems. The bulk of the research took place in the Beaufort and Chukchi seas in summer 2010 and 2011. Credit: NASA/Kathryn Hansen NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  12. Sampling Melt Ponds

    NASA Image and Video Library

    2017-09-27

    On July 10, 2011, Jens Ehn of Scripps Institution of Oceanography (left), and Christie Wood of Clark University (right), scooped water from melt ponds on sea ice in the Chukchi Sea. The water was later analyzed from the Healy's onboard science lab. The ICESCAPE mission, or "Impacts of Climate on Ecosystems and Chemistry of the Arctic Pacific Environment," is a NASA shipborne investigation to study how changing conditions in the Arctic affect the ocean's chemistry and ecosystems. The bulk of the research took place in the Beaufort and Chukchi seas in summer 2010 and 2011. Credit: NASA/Kathryn Hansen NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  13. CO₂ efflux from shrimp ponds in Indonesia.

    PubMed

    Sidik, Frida; Lovelock, Catherine E

    2013-01-01

    The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO₂) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO₂ efflux from the floors and walls of shrimp ponds. Rates of CO₂ efflux within shrimp ponds were 4.37 kg CO₂ m⁻² y⁻¹ from the walls and 1.60 kg CO₂ m⁻² y⁻¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO₂ emissions to the atmosphere between 5.76 and 13.95 Tg y⁻¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO₂ emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO₂ released to atmosphere.

  14. Sunlight and the 10-year incidence of age-related maculopathy: the Beaver Dam Eye Study.

    PubMed

    Tomany, Sandra C; Cruickshanks, Karen J; Klein, Ronald; Klein, Barbara E K; Knudtson, Michael D

    2004-05-01

    To examine the association of sunlight exposure and indicators of sun sensitivity with the 10-year incidence of age-related maculopathy (ARM). Population-based cohort study. We included persons aged 43 to 86 years at the baseline examination from 1988 to 1990, living in Beaver Dam, Wis, of whom 3684 persons underwent 5-year follow-up and 2764 underwent 10-year follow-up. Data on sun exposure and indicators of sun sensitivity were obtained from a standardized questionnaire administered at baseline and/or follow-up. We determined ARM status by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. Incidence and progression of ARM. While controlling for age and sex, we found that participants exposed to the summer sun for more than 5 hours a day during their teens, in their 30s, and at the baseline examination were at a higher risk of developing increased retinal pigment (risk ratio [RR], 2.99; 95% confidence interval [CI], 1.18-7.60; P =.02) and early ARM (RR, 2.20; 95% CI, 1.02-4.73; P =.04) [corrected] by 10 years than those exposed less than 2 hours per day during the same periods. In participants reporting the highest summer sun exposure levels in their teens and 30s, the use of hats and sunglasses at least half the time during the same periods was associated with a decreased risk of developing soft indistinct drusen (RR, 0.55; 95% CI, 0.33-0.90; P =.02) and retinal pigment epithelial depigmentation (RR, 0.51; 95% CI, 0.29-0.91; P =.02). Participants who experienced more than 10 severe sunburns during their youth were more likely than those who experienced 1 or no burn to develop drusen with a 250-microm diameter or larger (RR, 2.52; 95% CI, 1.29-4.94 [corrected] P =.01) by the 10-year examination. No relationships were found between UV-B exposure, winter leisure time spent outdoors, skin sun sensitivity, or number of bad sunburns experienced by the time of the baseline examination and the 10-year incidence and

  15. Linkage Analysis of Quantitative Refraction and Refractive Errors in the Beaver Dam Eye Study

    PubMed Central

    Duggal, Priya; Lee, Kristine E.; Cheng, Ching-Yu; Klein, Ronald; Bailey-Wilson, Joan E.; Klein, Barbara E. K.

    2011-01-01

    Purpose. Refraction, as measured by spherical equivalent, is the need for an external lens to focus images on the retina. While genetic factors play an important role in the development of refractive errors, few susceptibility genes have been identified. However, several regions of linkage have been reported for myopia (2q, 4q, 7q, 12q, 17q, 18p, 22q, and Xq) and for quantitative refraction (1p, 3q, 4q, 7p, 8p, and 11p). To replicate previously identified linkage peaks and to identify novel loci that influence quantitative refraction and refractive errors, linkage analysis of spherical equivalent, myopia, and hyperopia in the Beaver Dam Eye Study was performed. Methods. Nonparametric, sibling-pair, genome-wide linkage analyses of refraction (spherical equivalent adjusted for age, education, and nuclear sclerosis), myopia and hyperopia in 834 sibling pairs within 486 extended pedigrees were performed. Results. Suggestive evidence of linkage was found for hyperopia on chromosome 3, region q26 (empiric P = 5.34 × 10−4), a region that had shown significant genome-wide evidence of linkage to refraction and some evidence of linkage to hyperopia. In addition, the analysis replicated previously reported genome-wide significant linkages to 22q11 of adjusted refraction and myopia (empiric P = 4.43 × 10−3 and 1.48 × 10−3, respectively) and to 7p15 of refraction (empiric P = 9.43 × 10−4). Evidence was also found of linkage to refraction on 7q36 (empiric P = 2.32 × 10−3), a region previously linked to high myopia. Conclusions. The findings provide further evidence that genes controlling refractive errors are located on 3q26, 7p15, 7p36, and 22q11. PMID:21571680

  16. Linkage analysis of quantitative refraction and refractive errors in the Beaver Dam Eye Study.

    PubMed

    Klein, Alison P; Duggal, Priya; Lee, Kristine E; Cheng, Ching-Yu; Klein, Ronald; Bailey-Wilson, Joan E; Klein, Barbara E K

    2011-07-13

    Refraction, as measured by spherical equivalent, is the need for an external lens to focus images on the retina. While genetic factors play an important role in the development of refractive errors, few susceptibility genes have been identified. However, several regions of linkage have been reported for myopia (2q, 4q, 7q, 12q, 17q, 18p, 22q, and Xq) and for quantitative refraction (1p, 3q, 4q, 7p, 8p, and 11p). To replicate previously identified linkage peaks and to identify novel loci that influence quantitative refraction and refractive errors, linkage analysis of spherical equivalent, myopia, and hyperopia in the Beaver Dam Eye Study was performed. Nonparametric, sibling-pair, genome-wide linkage analyses of refraction (spherical equivalent adjusted for age, education, and nuclear sclerosis), myopia and hyperopia in 834 sibling pairs within 486 extended pedigrees were performed. Suggestive evidence of linkage was found for hyperopia on chromosome 3, region q26 (empiric P = 5.34 × 10(-4)), a region that had shown significant genome-wide evidence of linkage to refraction and some evidence of linkage to hyperopia. In addition, the analysis replicated previously reported genome-wide significant linkages to 22q11 of adjusted refraction and myopia (empiric P = 4.43 × 10(-3) and 1.48 × 10(-3), respectively) and to 7p15 of refraction (empiric P = 9.43 × 10(-4)). Evidence was also found of linkage to refraction on 7q36 (empiric P = 2.32 × 10(-3)), a region previously linked to high myopia. The findings provide further evidence that genes controlling refractive errors are located on 3q26, 7p15, 7p36, and 22q11.

  17. Malaria and pond-based rainwater harvesting linkages in the fringes of central highland Ethiopia.

    PubMed

    Kassahun Waktola, D

    2008-01-01

    Several studies have unravelled the linkages between malaria and macro-sized water bodies (lakes, dams, irrigations) in various parts of tropical Africa. However, those findings cannot be extrapolated to areas where micro-sized rainwater harvesting (RWH) ponds are dominant. This article reveals the linkages between malaria and RWH in some parts of central Ethiopia where micro-level irrigation is practised. A descriptive study was conducted in five sample districts of Amhara and Oromia states. Systematic random sampling was employed to select 300 households. Data were collected using household survey, focus group discussion and key informant interview techniques. The launch of RWH in the surveyed area, coupled with warming regional temperatures, has created breeding pools for mosquitoes and a longer malaria transmission period. The location of RWH ponds, the type of pond covers in use, and the limitations of some government policies are among the factors respondents believe have lead to an expansion of malaria incidence in recent years. Users and non-users of RWH varied on the malaria-RWH nexus, which could be attributed to RWH-induced socioeconomic differences. Given the growing need for micro-level irrigated agriculture to feed a rapidly growing tropical population, coupled with a predicted warming of global and regional air temperatures, this study suggests a need for further investigation on a broader scale.

  18. Gas transfer velocities in small forested ponds

    NASA Astrophysics Data System (ADS)

    Holgerson, Meredith A.; Farr, Emily R.; Raymond, Peter A.

    2017-05-01

    Inland waters actively exchange gases with the atmosphere, and the gas exchange rate informs system biogeochemistry, ecology, and global carbon budgets. Gas exchange in medium- to large-sized lakes is largely regulated by wind; yet less is known about processes regulating gas transfer in small ponds where wind speeds are low. In this study, we determined the gas transfer velocity, k600, in four small (<250 m2) ponds by using a propane (C3H8) gas injection. When estimated across 12 h periods, the average k600 ranged from 0.19 to 0.72 m d-1 across the ponds. We also estimated k600 at 2 to 3 h intervals during the day and evaluated the relationship with environmental conditions. The average daytime k600 ranged from 0.33 to 1.83 m d-1 across the ponds and was best predicted by wind speed and air or air-water temperature; however, the explanatory power was weak (R2 < 0.27) with high variability within and among ponds. To compare our results to larger water bodies, we compiled direct measurements of k600 from 67 ponds and lakes worldwide. Our k600 estimates were within the range of estimates for other small ponds, and variability in k600 increased with lake size. However, the majority of studies were conducted on medium-sized lakes (0.01 to 1 km2), leaving small ponds and large lakes understudied. Overall, this study adds four small ponds to the existing body of research on gas transfer velocities from inland waters and highlights uncertainty in k600, with implications for calculating metabolism and carbon emissions in inland waters.

  19. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed Central

    Kuzishchin, Kirill V.; Stanford, Jack A.

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3–12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99–1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  20. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed

    Malison, Rachel L; Kuzishchin, Kirill V; Stanford, Jack A

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3-12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99-1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  1. 1. VIEW OF THE MILL TAILINGS FACING NORTHWEST. SEDIMENT DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF THE MILL TAILINGS FACING NORTHWEST. SEDIMENT DAM AND POND IN THE FOREGROUND, AND WATER PUMP (FEATURE B-25) ON THE LOWER RIGHT SIDE OF PHOTO. - Nevada Lucky Tiger Mill & Mine, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  2. 5. Aerial view west, Adams Dam Road bottom center, State ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Aerial view west, Adams Dam Road bottom center, State Route 100 center, duck pond and reservoir center, State Route 100 center right, State Route 92 below center right, Brandywine Creek State Park center bottom. - Winterthur Farms, Intersection State Routes 92 & 100, Intersection State Routes 92 & 100, Winterthur, New Castle County, DE

  3. 4. Aerial view southwest, Adams Dam Road bottom left, State ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Aerial view southwest, Adams Dam Road bottom left, State Route 100 center, back gates to Winterthur and Wilmington Country Club upper center, duck pond and reservoir bottom right and center, and State Route 92 center bottom. - Winterthur Farms, Intersection State Routes 92 & 100, Intersection State Routes 92 & 100, Winterthur, New Castle County, DE

  4. 7. DETAIL OF SOUTH ELEVATION OF DAM WALL, SHOWING WATER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL OF SOUTH ELEVATION OF DAM WALL, SHOWING WATER FLOW AND PORTION OF WEST PARAPET WALL, LOOKING NORTHWEST - Whitman Estate, Lower Pond Spillway, Approx. .5 mile south of intersection of DE72 & Ebeneezer Church Road, Newark, New Castle County, DE

  5. Assessment of dam impacts on sediment dynamics and channel geometry in complex anthropogenic systems: feedbacks from comparative study of the Sacramento and the Ain Rivers

    NASA Astrophysics Data System (ADS)

    Rollet, A. J.; Piégay, H.; Michalkova, M.; Kondolf, G. M.

    2009-04-01

    Numerous studies have demonstrated the complexity of river adjustments downstream dams (Williams and Wolman, 1984; Brandt, 2000; Petts and Gurnell, 2005), depending on many parameters such catchment geology context (Grant et al., 2003), land use, pre-dam sediment supply and transport regime, degree of hydrologic alteration (Church, 1995; Schmidt and Wilcock, 2008), and dam characteristics and operation (Brewer and Lewin, 1998). Dam impact is particularly difficult to evaluate in river systems where human pressures are old and manifold, and where dam-induced impacts can be compounded by other human influences, such as in-channel aggregate mining (Kondolf 1997). In such cases, it may be challenging to sort out the causal links between dam-induced disruptions and resulting channel adjustment. To illustrate these problems, we introduce two complex case studies, the Ain (France) and Sacramento (California) Rivers, both freely meandering rivers regulated since mid-20th century, whose sedimentary and morphologic dynamic have been modified in different ways since the end of the 19th century. Dam impacts can be distinguished from the effects of other factors such as floodplain disconnection by flood-control infrastructure, land-use changes, and artificial meander-bend cutoff. The Ain River evinces a significant sediment deficit, which results in bed degradation, decrease in area of gravel bars , and reduced lateral channel migration. As a result, sediment supply is reduced not only from trapping by upstream reservoirs but also by reduced bank erosion. In the case of the Sacramento, the impact of the dam is not as clear as on the Ain due to major effects of prior pressures on the channel. Using aerial imagery and field measurements (grain-size measurements…), we led a spatiotemporal study of several morphologic parameters (active channel narrowing, gravel bar areas …) to underline the relative contribution of dams to the contemporary channel evolution. These analyses are

  6. Photosynthesis and fish production in culture ponds

    SciTech Connect

    Szyper, J.P.

    1995-12-31

    The widely-cultured Nile tilapia, Oreochromis niloticus, has been the major species used in standardized experiments by the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/ACRSP). Yields of Nile Tilapia from fertilized, unfed ponds have served as a bioassay for effectiveness of pond management protocols developed during worldwide tropical experiments. Yield rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates of primary production. Fish production is related to daytime net photosynthetic production, but it is not clear whether production of food materials or oxygen is the more direct influence. Excessively high standing stocks of phytoplankton are not the best net producers, and increase and risk of nighttime oxygen depletion. Fish readily grow to individual sizes of 200-300 g/fish in fertilized ponds, which is sufficient market size in many locations. Supplemental feeding of caged or free-ranging fish greatly accelerates growth beyond 300 g and potentiates high areal yields; the PD/A CRSP has also developed efficient feeding regimes and shown that supplemental feeding need not begin before fish reach 200 g weight. High standing stocks of phytoplankton and high photosynthetic rates in eutrophic ponds make study of photosynthesis possible without radioisotopes. Such ponds also exhibit complete extinction of incident solar radiation within shallow depths, and vertical temperature structure resembling that of deeper bodies of water. These characteristics make ponds useful as microcosms for study of some aspects of photosynthesis in natural waters.

  7. Msx genes are expressed in the carapacial ridge of turtle shell: a study of the European pond turtle, Emys orbicularis.

    PubMed

    Vincent, Christine; Bontoux, Martine; Le Douarin, Nicole M; Pieau, Claude; Monsoro-Burq, Anne-Hélène

    2003-09-01

    The turtle shell forms by extensive ossification of dermis ventrally and dorsally. The carapacial ridge (CR) controls early dorsal shell formation and is thought to play a similar role in shell growth as the apical ectodermal ridge during limb development. However, the molecular mechanisms underlying carapace development are still unknown. Msx genes are involved in the development of limb mesenchyme and of various skeletal structures. In particular, precocious Msx expression is recorded in skeletal precursors that develop close to the ectoderm, such as vertebral spinous processes or skull. Here, we have studied the embryonic expression of Msx genes in the European pond turtle, Emys orbicularis. The overall Msx expression in head, limb, and trunk is similar to what is observed in other vertebrates. We have focused on the CR area and pre-skeletal shell condensations. The CR expresses Msx genes transiently, in a pattern similar to that of fgf10. In the future carapace domain, the dermis located dorsal to the spinal cord expresses Msx genes, as in other vertebrates, but we did not see expansion of this expression in the dermis located more laterally, on top of the dermomyotomes. In the ventral plastron, although the dermal osseous condensations form in the embryonic Msx-positive somatopleura, we did not observe enhanced Msx expression around these elements. These observations may indicate that common mechanisms participate in limb bud and CR early development, but that pre-differentiation steps differ between shell and other skeletal structures and involve other gene activities than that of Msx genes.

  8. Economic Efficiency and Equity in Dams Removal: Case studies in Northeastern Massachusetts Doina Oglavie, Ellen Douglas, David Terkla

    NASA Astrophysics Data System (ADS)

    Oglavie, D. R.; Douglas, E. M.; Terkla, D.

    2009-12-01

    According to American Rivers (www.americanrivers.org), Massachusetts has almost 3,000 dams under state regulation, 296 of which have been classified as high hazard, meaning they pose a serious threat to human life if they should fail. Most of these dams, however, are low head, “run-of-the-river” dams that no longer serve the purpose for which they were built. The presence of these dams has fragmented aquatic and riparian ecosystems, impeded fish passage and generally impacted the natural ecological and hydrological functioning of the streams in which they reside. Dam removal should be considered when a dam no longer serves its function. Although in many cases, the removal of a dam is environmentally beneficial (at least over the long term), sometimes the removal of a dam can incur environmental costs, such as release of contaminants that were sequestered behind the dam. Dam removal is a complex issue especially with respect to privately owned dams. In many cases, dam removal is less costly than dam maintenance or upgrade, hence dam removal decisions tend to be based on purely monetary considerations, and the environmental costs or benefits associated with the dam are not considered. Typically, the main objective for the dam owner is to incur the lowest possible cost (private cost), whether it be operating and maintenance or removal; external costs (environmental degradation) are rarely, if ever, considered, hence the true cost to society is not included in the economic analysis. If dam operation and removal decisions are to be economically efficient, then they have to include both the private costs as well as the external (environmental) costs. The purpose of this work is to 1) attempt to quantify the externalities associated with the maintenance and the removal of dams, 2) assess whether or not the current dam removal evaluation process maximizes social welfare (efficiency and equity) and 3) suggest ways in which this process can be improved by including the

  9. Determining the Population Size of Pond Phytoplankton.

    ERIC Educational Resources Information Center

    Hummer, Paul J.

    1980-01-01

    Discusses methods for determining the population size of pond phytoplankton, including water sampling techniques, laboratory analysis of samples, and additional studies worthy of investigation in class or as individual projects. (CS)

  10. Combining mariculture and seawater-based solar ponds

    SciTech Connect

    Lowrey, P.; Ford, R.; Collando, F.; Morgan, J.; Frusti, E. . Dept. of Mechanical Engineering)

    1990-05-01

    Solar ponds have been thoroughly studied as a means to produce electricity or heat, but there may be comparable potential to use solar ponds to produce optimized environments for the cultivation of some aquaculture crops. For this, conventional brine-based solar ponds could be used. This strategy would probably be most suitable at desert sites where concentrated brine was abundant, pond liners might not be needed, and the crop produced could be shipped to market. Generally, a heat exchanger would be required to transfer heat from the solar pond into the culture ponds. Culture ponds could therefore use either fresh or marine water. In contrast, this paper explores seawater-based solar ponds. These are solar ponds which use seawater in the bottom storage zone and fresh water in the upper convective zone. Because the required temperature elevations for mariculture are only about 10{degrees}C, seawater-based solar ponds are conceivable. Seawater-based ponds should be very inexpensive because, by the shore, salt costs would be negligible and a liner might be unnecessary.

  11. Large-scale projects in the amazon and human exposure to mercury: The case-study of the Tucuruí Dam.

    PubMed

    Arrifano, Gabriela P F; Martín-Doimeadios, Rosa C Rodríguez; Jiménez-Moreno, María; Ramírez-Mateos, Vanesa; da Silva, Núbia F S; Souza-Monteiro, José Rogério; Augusto-Oliveira, Marcus; Paraense, Ricardo S O; Macchi, Barbarella M; do Nascimento, José Luiz M; Crespo-Lopez, Maria Elena

    2017-08-28

    The Tucuruí Dam is one of the largest dams ever built in the Amazon. The area is not highly influenced by gold mining as a source of mercury contamination. Still, we recently noted that one of the most consumed fishes (Cichla sp.) is possibly contaminated with methylmercury. Therefore, this work evaluated the mercury content in the human population living near the Tucuruí Dam. Strict exclusion/inclusion criteria were applied for the selection of participants avoiding those with altered hepatic and/or renal functions. Methylmercury and total mercury contents were analyzed in hair samples. The median level of total mercury in hair was above the safe limit (10µg/g) recommended by the World Health Organization, with values up to 75µg/g (about 90% as methylmercury). A large percentage of the participants (57% and 30%) showed high concentrations of total mercury (≥ 10µg/g and ≥ 20µg/g, respectively), with a median value of 12.0µg/g. These are among the highest concentrations ever detected in populations living near Amazonian dams. Interestingly, the concentrations are relatively higher than those currently shown for human populations highly influenced by gold mining areas. Although additional studies are needed to confirm the possible biomagnification and bioaccumulation of mercury by the dams in the Amazon, our data already support the importance of adequate impact studies and continuous monitoring. More than 400 hydropower dams are operational or under construction in the Amazon, and an additional 334 dams are presently planned/proposed. Continuous monitoring of the populations will assist in the development of prevention strategies and government actions to face the problem of the impacts caused by the dams. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The formation and failure of debris flow-dams, background, key factors and model tests: case studies from China

    NASA Astrophysics Data System (ADS)

    Dang, Chao; Cui, Peng; Cheng, Zun-Lan

    2009-06-01

    Temporary dams can be formed by the sudden injection of debris flow into main streams by some favorable geomorphologic and hydraulic conditions, resulting in extensive inundations upstream and catastrophic floods downstream due to dam breaches and consequently dramatic changes of channels and valleys. Expeditious means of assessing dam-forming potential are necessary, particularly in geologically active regions. Complete blockages or dam formations are significantly related to the discharge ratio and velocity ratio between the tributary and the main stream, the bulk density of the debris flow, confluent angles and the degree of unevenness of grain sizes. In order to set up a critical index/ C for dam formation, 19 groups of flume tests were conducted. The results showed that there were three types of blockage in the intersections, and dam-forming processes were mainly controlled by the product of the dimensionless momentum ratio and the degree of unevenness of grain sizes in the debris flow. Complete blockages or dam formations occurred when C > 83.4, whereas semi-blockages were formed or no dams were formed when C < 71.5, which had been judged to be feasible by historical instances of dam formation in China. Dam failures commonly resulted from overtopping. No piping was observed in the course of dam failure, and the time elapsed between dams can be denoted by a linear relation with the momentum ratio.

  13. Influence of Partial Dam Removal on Change of Channel Morphology and Physical Habitats: A Case Study of Yu-Sheng River

    NASA Astrophysics Data System (ADS)

    Hao Weng, Chung; Yeh, Chao Hsien

    2017-04-01

    The rivers in Taiwan have the characteristic of large slope gradient and fast flow velocity caused by rugged terrain. And Taiwan often aces many typhoons which will bring large rainfall in the summer. In early Taiwan, river management was more focus on flood control, flood protection and disaster reduction. In recent years, the rise of ecological conservation awareness for the precious fish species brings spotlight on the Taiwan salmon (Oncorhynchus masou formosanus) which lives in the river section of this study. In order to make sure ecological corridor continuing, dam removal is the frequently discussed measure in recent years and its impact on environmental is also highly concerned. Since the dam removal may causes severe changes to the river channel, the action of dam removal needs careful evaluation. As one of the endangered species, Taiwan salmon is considered a national treasure of Taiwan and it was originally an offshore migration of the Pacific salmon. After the ice age and geographical isolation, it becomes as an unique subspecies of Taiwan and evolved into landlocked salmon. Now the Taiwan salmon habitats only exists in few upstream creeks and the total number of wild Taiwan salmon in 2015 was about 4,300. In order to expand the connectivity of the fish habitats in Chi-Jia-Wan creek basin, several dam removal projects had completed with good results. Therefore, this paper focuses on the dam removal of Yu-Sheng creek dam. In this paper, a digital elevation model (DEM) of about 1 kilometer channel of the Yu-Sheng creek dam is obtained by unmanned aerial vehicle (UAV). Using CCHE2D model, the simulation of dam removal will reveal the impact on channel morphology. After model parameter identification and verification, this study simulated the scenarios of three historical typhoon events with recurrence interval of two years, fifteen years, and three decades under four different patterns of dam removal to identify the the head erosion, flow pattern, and

  14. Urban ponds as an aquatic biodiversity resource in modified landscapes.

    PubMed

    Hill, Matthew J; Biggs, Jeremy; Thornhill, Ian; Briers, Robert A; Gledhill, David G; White, James C; Wood, Paul J; Hassall, Christopher

    2017-03-01

    Urbanization is a global process contributing to the loss and fragmentation of natural habitats. Many studies have focused on the biological response of terrestrial taxa and habitats to urbanization. However, little is known regarding the consequences of urbanization on freshwater habitats, especially small lentic systems. In this study, we examined aquatic macro-invertebrate diversity (family and species level) and variation in community composition between 240 urban and 782 nonurban ponds distributed across the United Kingdom. Contrary to predictions, urban ponds supported similar numbers of invertebrate species and families compared to nonurban ponds. Similar gamma diversity was found between the two groups at both family and species taxonomic levels. The biological communities of urban ponds were markedly different to those of nonurban ponds, and the variability in urban pond community composition was greater than that in nonurban ponds, contrary to previous work showing homogenization of communities in urban areas. Positive spatial autocorrelation was recorded for urban and nonurban ponds at 0-50 km (distance between pond study sites) and negative spatial autocorrelation was observed at 100-150 km and was stronger in urban ponds in both cases. Ponds do not follow the same ecological patterns as terrestrial and lotic habitats (reduced taxonomic richness) in urban environments; in contrast, they support high taxonomic richness and contribute significantly to regional faunal diversity. Individual cities are complex structural mosaics which evolve over long periods of time and are managed in diverse ways. This facilitates the development of a wide range of environmental conditions and habitat niches in urban ponds which can promote greater heterogeneity between pond communities at larger scales. Ponds provide an opportunity for managers and environmental regulators to conserve and enhance freshwater biodiversity in urbanized landscapes whilst also facilitating

  15. Trapping efficiency of three types check dams experiment

    NASA Astrophysics Data System (ADS)

    Huang, Hui-Kai; CHEN, Su-Chin; AN, Hsuan-Pei

    2015-04-01

    The check dams constructed to trap debris flow. This study divide check dams into three types as closed-type check dam, slit dam, and modular steel check dam. Closed-type check dam which can trap all kind of sediment or driftwood. Slit check dam is permeable dam, so it can prevent from depositing all of sediment or driftwood. A modular steel check dam improves the existing hard-to-change disadvantages of slit dam structure. The assembling of longitudinal and transverse beams can be constructed independently, and then it could be freely configured to form a flexibly adjustable modular steel check dam. This study used the laws of geometric similitude to design model of dam. To explore the trapping mechanisms and phenomenon in different dismantle transverse beams conditions and compared the trapping efficiency with different type of check dams. This study used different volume ratio with driftwood and sediment. In order to capture the trace of debris flow and calculate accuracy velocity of debris flow the study used several high-speed photography combining the method of 3D Remodeling from Motion Structure with Multi-View Stereo which constructed with multiple photos of overlapping coefficient at least 70% and established three-dimensional system of coordinate in laboratory experiment. As a result, the driftwood deposition rate of modular steel check dam increase 60% than slit dam and 40% than closed-type dam; the debris deposition rate increase 30% than slit dam. In addition, the increment of driftwood volume ratio led to the increment of trapping efficiency of three type of check dams. Meanwhile slit dam is the most effective type in trapping driftwood and sediment with more than 50% of increased rate, because of more driftwood flow through the slit dam jam together easily. Finally, transverse beams which installed the modular steel check dam can suppress the upward movement of driftwood, therefore driftwood can easily form the arched stacking efficiency with

  16. Nonlinear Seismic Analysis of Morrow Point Dam

    SciTech Connect

    Noble, C R; Nuss, L K

    2004-02-20

    This research and development project was sponsored by the United States Bureau of Reclamation (USBR), who are best known for the dams, power plants, and canals it constructed in the 17 western states. The mission statement of the USBR's Dam Safety Office, located in Denver, Colorado, is ''to ensure Reclamation dams do not present unacceptable risk to people, property, and the environment.'' The Dam Safety Office does this by quickly identifying the dams which pose an increased threat to the public, and quickly completing the related analyses in order to make decisions that will safeguard the public and associated resources. The research study described in this report constitutes one element of USBR's research and development work to advance their computational and analysis capabilities for studying the response of dams to strong earthquake motions. This project focused on the seismic response of Morrow Point Dam, which is located 263 km southwest of Denver, Colorado.

  17. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2004-2005 Annual Report.

    SciTech Connect

    Smith, Steven G.; Muir, William D.; Marsh, Douglas M.

    2005-10-01

    In 2004, the National Marine Fisheries Service and the University of Washington completed the twelfth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder tags (PIT tags). We PIT tagged and released a total of 19,621 hatchery steelhead, 8,128 wild steelhead, and 9,227 wild yearling Chinook salmon at Lower Granite Dam. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the single-release model). Primary research objectives in 2004 were to (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon O. tshawytscha and steelhead O. mykiss; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2004 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures; details on methodology and statistical models used are provided in previous reports cited here. Survival and detection probabilities were estimated precisely for most of the 2004 yearling Chinook salmon and steelhead migrations. Hatchery and

  18. Delineation of subsurface structures using resistivity, VLF and radiometric measurement around a U-tailings pond and its hydrogeological implication

    NASA Astrophysics Data System (ADS)

    Banerjee, K. S.; Sharma, S. P.; Sarangi, A. K.; Sengupta, D.

    The hydrogeological characteristics of the uranium mill tailings pond in the vicinity of Jaduguda (Jharkhand, India) were investigated to examine possible contamination and suggest suitable remedial measures, if required. As the hydrogeological characteristics of subsurface geology are closely related to the electrical properties of the subsurface, geophysical measurements using electrical resistivity coupled with Very Low Frequency electromagnetic method and radiation study were used to investigate the geophysical and geological condition of mill tailings in order to characterize the subsurface structures of the tailings pond. The resistivity interpretation depicted the thickness of the soil cover and thickness of tailings in the pond, as well as the depth to the basement. It also suggested the possible flow direction of leachate. It was observed that the resistivity of the top layer decreases in the direction opposite to the dam axis, which in turn, indicated that the groundwater movement occurs in the opposite direction of the dam axis (in the northwest direction). The VLF method depicted the fractures through which groundwater moves, and also showed the current density alignment in the northwest direction at 10 m depth. The radiation measurement showed relatively higher counts in the northwest direction. This correlated well with the resistivity measurement. The current density at a depth of 20 m showed a closed contour suggesting no groundwater movement in the area at this depth, and that high conductivity material was confined to the tailings area only. It was concluded that groundwater moves in opposite direction of the dam axis at shallower depth only. It was found that continuation of fractures do not extend to deeper depths, which suggested that the tailings storage facility at Jaduguda was reasonably safe from any downward contamination.

  19. Post-treatment of UASB reactor effluent in waste stabilization ponds and in horizontal flow constructed wetlands: a comparative study in pilot scale in Southeast Brazil.

    PubMed

    Bastos, R K X; Calijuri, M L; Bevilacqua, P D; Rios, E N; Dias, E H O; Capelete, B C; Magalhães, T B

    2010-01-01

    The results of a 20-month period study in Brazil were analyzed to compare horizontal-flow constructed wetlands (CW) and waste stabilization pond (WSP) systems in terms of land area requirements and performance to produce effluent qualities for surface water discharge, and for wastewater use in agriculture and/or aquaculture. Nitrogen, E. coli and helminth eggs were more effectively removed in WSP than in CW. It is indicated that CW and WSP require similar land areas to achieve a bacteriological effluent quality suitable for unrestricted irrigation (10(3) E. coli per 100 mL), but CW would require 2.6 times more land area than ponds to achieve quite relaxed ammonia effluent discharge standards (20 mg NH(3) L(-1)), and, by far, more land than WSP to produce an effluent complying with the WHO helminth guideline for agricultural use (< or =1 egg per litre).

  20. Evaluating the performance of a retrofitted stormwater wet pond for treatment of urban runoff.

    PubMed

    Schwartz, Daniel; Sample, David J; Grizzard, Thomas J

    2017-06-01

    This paper describes the performance of a retrofitted stormwater retention pond (Ashby Pond) in Northern Virginia, USA. Retrofitting is a common practice which involves modifying existing structures and/or urban landscapes to improve water quality treatment, often compromising standards to meet budgetary and site constraints. Ashby Pond is located in a highly developed headwater watershed of the Potomac River and the Chesapeake Bay. A total maximum daily load (TMDL) was imposed on the Bay watershed by the US Environmental Protection Agency in 2010 due to excessive sediment and nutrient loadings leading to eutrophication of the estuary. As a result of the TMDL, reducing nutrient and sediment discharged loads has become the key objective of many stormwater programs in the Bay watershed. The Ashby Pond retrofit project included dredging of accumulated sediment to increase storage, construction of an outlet structure to control flows, and repairs to the dam. Due to space limitations, pond volume was less than ideal. Despite this shortcoming, Ashby Pond provided statistically significant reductions of phosphorus, nitrogen, and suspended sediments. Compared to the treatment credited to retention ponds built to current state standards, the retrofitted pond provided less phosphorus but more nitrogen reduction. Retrofitting the existing stock of ponds in a watershed to at least partially meet current design standards could be a straightforward way for communities to attain downstream water quality goals, as these improvements represent reductions in baseline loads, whereas new ponds in new urban developments simply limit future load increases or maintain the status quo.

  1. A case study investigating the occurrence of geosmin and 2-methylisoborneol (MIB) in the surface waters of the Hinze Dam, Gold Coast, Australia.

    PubMed

    Uwins, H K; Teasdale, P; Stratton, H

    2007-01-01

    The Hinze Dam is located in the Gold Coast hinterland and is the primary source of water supply for the Gold Coast region. Sporadic and unpredictable taste and odour events caused by geosmin and 2-methylisoborneol (MIB) are an ongoing problem in the Hinze Dam. To investigate potential ecological and physiological triggers of these events, a 12-month surface-sampling regime was undertaken. Concentrations of geosmin, MIB, nitrogen and phosphorus were measured. Algal and cyanobacterial counts were performed. Water temperature, rainfall and dam capacity were also recorded. The occurrence of geosmin was found to correlate significantly with Anabaena numbers, water temperature and dam capacity. The occurrence of MIB correlated with increasing ammonia. No significant correlations were observed with the other nutrients or physical parameters measured. Overall, this study demonstrated that high concentrations of geosmin detected in dam surface waters was strongly correlated with an increase in numbers of Anabaena spp. These events were most likely triggered by significant rainfall causing a pulse in nutrients into the dam, in conjunction with warmer water temperatures.

  2. POND MOUNTAIN AND POND MOUNTAIN ADDITION ROADLESS AREAS, TENNESSEE.

    USGS Publications Warehouse

    Griffitts, W.R.; Bitar, Richard

    1984-01-01

    As a result of a mineral study of the Pond Mountain Roadless Areas, Tennessee, a probable potential for the occurrence of tin, niobium, and tungsten resource with associated beryllium, molybdenum, zinc, and fluorite was identified in rocks of Precambrian age particularly in the southeastern part of the area. Detailed geologic mapping and geochemical sampling of the soils and rocks in the area of Precambrian rocks is recommended to identify and delimit the areas of potential resources of tin, niobium, and tungsten.

  3. Studies on phyto-and-zooplankton composition and its relation to fish productivity in a west coast fish pond ecosystem.

    PubMed

    Park, Kwan Soon; Shin, Hyun Woung

    2007-04-01

    A fish pond ecosystem on the west coast of Korea was studied for biotic and abiotic factors. The occurrence rate of phytoplankton at the embanked fish farm was 84 times higher to that of shore waters. Phytoplankton species which occurred during the study period were categorized into Cyanophyta, Dinophyta and Bacillariophyta with a total of 26 subgeneric taxa (22 species of Dinophyta, 2 species of Bacillariophyta and 2 species of Cyanophyta). The total cell density during the study period ranged from16 x 103 to 13.59 x 10(5) cells l(-1). As for the zooplankton, the monthly density ranged from 26 - 8.684 x 10(3) cells m(-3) with an average of 126.0 x 10(3) cells m(-3) for April. In the case of May, it ranged from 41 - 3.331 x 10(3) cells m(-3) and its average of 50.3 x 10(3) cells m(-3) which was comparatively less. The varying environmental factors in Seosan embankment A, B and Chonsu Bay waters could have affected the fish farm. According to the results, the concentration of inorganic nitrogen was 0.067-0.106 (average: 0.083) mg l(-1) and the concentration of organic nitrogen was 0.008-0.022 (average: 0.014) mgl(-1). Also due to the release of brackish water at Seosan embankment A and B, the inorganic nitrogen showed an increasing trend. The survival rate of Sabastes schlegeli, and Acanthopagrus schlegeli was high in stations 2H and I (20.87%, 33%) and relatively low in stations 2B to 2F.

  4. Reliablity analysis of gravity dams by response surface method

    NASA Astrophysics Data System (ADS)

    Humar, Nina; Kryžanowski, Andrej; Brilly, Mitja; Schnabl, Simon

    2013-04-01

    A dam failure is one of the most important problems in dam industry. Since the mechanical behavior of dams is usually a complex phenomenon existing classical mathematical models are generally insufficient to adequately predict the dam failure and thus the safety of dams. Therefore, numerical reliability methods are often used to model such a complex mechanical phenomena. Thus, the main purpose of the present paper is to present the response surface method as a powerful mathematical tool used to study and foresee the dam safety considering a set of collected monitoring data. The derived mathematical model is applied to a case study, the Moste dam, which is the highest concrete gravity dam in Slovenia. Based on the derived model, the ambient/state variables are correlated with the dam deformation in order to gain a forecasting tool able to define the critical thresholds for dam management.

  5. Simulated ground-water flow for a pond-dominated aquifer system near Great Sandy Bottom Pond, Pembroke, Massachusetts

    USGS Publications Warehouse

    Carlson, Carl S.; Lyford, Forest P.

    2005-01-01

    A ground-water flow simulation for a 66.4-square-mile area around Great Sandy Bottom (GSB) Pond (105 acres) near Pembroke, Massachusetts, was developed for use by local and State water managers to assess the yields for public water supply of local ponds and wells for average climatic and drought conditions and the effects of water withdrawals on nearby water levels and streamflows. Wetlands and ponds cover about 30 percent of the study area and the aquifer system is dominated by interactions between ground water and the ponds. The three largest surface-water bodies in the study area are Silver Lake (640 acres), Monponsett Pond (590 acres), and Oldham Pond (236 acres). The study area is drained by tributaries of the Taunton River to the southwest, the South and North Rivers to the northeast, and the Jones River to the southeast. In 2002, 10.8 million gallons per day of water was exported from ponds and 3.5 million gallons per day from wells was used locally for public supply. A transient ground-water-flow model with 69 monthly stress periods spanning the period from January 1998 through September 2003 was calibrated to stage at GSB Pond and nearby Silver Lake and streamflow and water levels collected from September 2002 through September 2003. The calibrated model was used to assess hydrologic responses to a variety of water-use and climatic conditions. Simulation of predevelopment (no pumping or export) average monthly (1949-2002) water-level conditions caused the GSB Pond level to increase by 6.3 feet from the results of a simulation using average 2002 pumping for all wells, withdrawals, and exports. Most of this decline can be attributed to pumping, withdrawals, and exports of water from sites away from GSB Pond. The effects of increasing the export rate from GSB Pond by 1.25 and 1.5 times the 2002 rate were a lowering of pond levels by a maximum of 1.6 and 2.8 feet, respectively. Simulated results for two different drought conditions, one mild drought similar to

  6. [Evaluation of cultural service value of aquaculture pond ecosystem: a case study in a water conservation area of Shanghai].

    PubMed

    Li, Sheng; Guo, Zong-xiang; Yang, Huai-yu; Yang, Zheng-yong

    2009-12-01

    Pond aquaculture has existed in China for thousands of years, which has not only contributed great economic value, but also presented cultural value for human beings. With the development and upgrading of Chinese economy and culture, these values will be highlighted further. To evaluate the cultural service value of pond aquaculture ecosystem would provide a scientific base to the policy-making to avoid or reduce the wrong design-making or avoid the policy-malfunction, and also, to promote the development of aquaculture and related recreational fishing industry, increase the added value of aquaculture and the income of fish-farmers, and promote the economic development of rural area. Based on the survey data from the aquaculture ponds in the water conservation area of Dianshan Lake in Qingpu District of Shanghai and the related statistical data, the cultural service value including recreational value and existence value of the aquaculture pond ecosystem in the area was estimated by means of travel cost method (TCM) and contingent valuation method (CVM). The total cultural service value of this ecosystem was about 213 million Yuan x a(-1) or 231296. 69 Yuan x hm(-2) x a(-1), being 5. 25 times of the market value of aquaculture products, among which, recreational value was about 189 million Yuan x a(-1), and existence value was about 24 million Yuan x a(-1). It was suggested that in the construction of new rural areas of Shanghai, sufficient attention should be paid on the full play of the cultural service value of aquaculture pond ecosystem.

  7. Influence of isolation on the recovery of pond mesocosms from the application of an insecticide. I. Study design and planktonic community responses.

    PubMed

    Hanson, Mark L; Graham, David W; Babin, Emmanuelle; Azam, Didier; Coutellec, Marie-Agnes; Knapp, Charles W; Lagadic, Laurent; Caquet, Thierry

    2007-06-01

    The influence of relative isolation on the ecological recovery of freshwater outdoor mesocosm communities after an acute toxic stress was assessed in a 14-month-long study. A single concentration of deltamethrin was applied to 8 out of 16 outdoor 9-m3 mesocosms to create a rapid decrease of the abundance of arthropods. To discriminate between external and internal recovery mechanisms, four treated and four untreated (control) mesocosms were covered with 1-mm mesh screen lids. The dynamics of planktonic communities were monitored in the four types of ponds. The abundance of many phytoplankton taxa increased after deltamethrin addition, but the magnitude of most increases was relatively small, probably due to low nutrient availability and the survival of rotifers. The greatest impact on zooplankton was seen in Daphniidae and, to a lesser extent, calanoid copepods. Recovery (defined as when statistical analysis failed to detect a difference in the abundance between the deltamethrin-treated ponds and corresponding control ponds for two consecutive sampling dates) of Daphniidae was observed in the water column 105 and 77 d after deltamethrin addition in open and covered mesocosms, respectively, and <42 d for both open and covered ponds at the surface of the sediments. Rotifers did not proliferate, probably because of the survival of predators (e.g., cyclopoid copepods). These results confirm that the recovery of planktonic communities after exposure to a strong temporary chemical stress mostly depends upon internal mechanisms (except for larvae of the insect Chaoborus sp.) and that recovery dynamics are controlled by biotic factors, such as the presence of dormant forms and selective survival of predators.

  8. A framework for social impact analysis of large dams: a case study of cascading dams on the Upper-Mekong River, China.

    PubMed

    Wang, Pu; Lassoie, James P; Dong, Shikui; Morreale, Stephen J

    2013-03-15

    Construction of large dams on the Upper-Mekong River, China, has significant social impacts on local communities. To analyze the social impacts, we identified three classes of wealth for the affected people, material, embodied, and relational, and comprehensively compared the loss and compensation in each type of wealth. Then we examined the effects on gap of wealth at household and community levels. Lastly, an insider-outsider analysis was conducted to understand the differences in the perceptions of wealth loss between local villagers and policy makers, and recommendations for more reasonable compensation policies were provided.

  9. Less rain, more water in ponds: a remote sensing study of the dynamics of surface waters from 1950 to present in pastoral Sahel (Gourma region, Mali)

    NASA Astrophysics Data System (ADS)

    Gardelle, J.; Hiernaux, P.; Kergoat, L.; Grippa, M.

    2010-02-01

    Changes in the flooded area of ponds in the Gourma region from 1950 to present are studied by remote sensing, in the general context of the current multi-decennial Sahel drought. The seasonal and interannual variations of the areas covered by surface water are assessed using multi-date and multi-sensor satellite images (SPOT, FORMOSAT, LANDSAT-MSS, -TM, and -ETM, CORONA, and MODIS) and aerial photographs (IGN). Water body classification is adapted to each type of spectral resolution, with or without a middle-infrared band, and each spatial resolution, using linear unmixing for mixed pixels of MODIS data. The high-frequency MODIS data document the seasonal cycle of flooded areas, with an abrupt rise early in wet season and a progressive decrease in the dry season. They also provide a base to study the inter-annual variability of the flooded areas, with sharp contrasts between dry years such as 2004 (low and early maximal area) and wetter years such as 2001 and 2002 (respectively high and late maximal area).The highest flooded area reached annually greatly depends on the volume, intensity and timing of rain events. However, the overall reduction by 20% of annual rains during the last 40 years is concomitant with an apparently paradoxical large increase in the area of surface water, starting from the 1970's and accelerating in the mid 1980's. Spectacular for the two study cases of Agoufou and Ebang Mallam, for which time series covering the 1954 to present period exist, this increase is also diagnosed at the regional scale from LANDSAT data spanning 1972-2007. It reaches 108% between September 1975 and 2002 for 91 ponds identified in central Gourma. Ponds with turbid waters and no aquatic vegetation are mostly responsible for this increase, more pronounced in the centre and north of the study zone. Possible causes of the differential changes in flooded areas are discussed in relation with the specifics in topography, soil texture and vegetation cover over the

  10. Less rain, more water in ponds: a remote sensing study of the dynamics of surface waters from 1950 to present in pastoral Sahel (Gourma region, Mali)

    NASA Astrophysics Data System (ADS)

    Gardelle, J.; Hiernaux, P.; Kergoat, L.; Grippa, M.

    2009-07-01

    Changes in the flood regime of ponds in the Gourma region from 1950 to present are studied by remote sensing, in the general context of the current multi-decennial Sahel drought. The seasonal and interannual variations of the areas covered by surface water are assessed using multi-date and multi-sensor satellite images (SPOT, FORMOSAT, LANDSAT-MSS, -TM, and -ETM, CORONA, and MODIS) and aerial photographs (IGN). Water body classification is adapted to each type of spectral resolution, with or without a middle-infrared band, and each spatial resolution, using linear unmixing for mixed pixels of MODIS data. The high-frequency MODIS data document the seasonal cycle, with an abrupt rise early in wet season and a progressive decrease in the dry season. They also provide a base to study the inter-annual variability of the flood regime, with sharp contrasts between dry years such as 2004 (low and early maximal area) and wetter years such as 2001 and 2002 (respectively high and late maximal area). The highest water level reached annually greatly depends on the volume, intensity and timing of rain events. However, the overall reduction by 20% of annual rains of the current period, compared to the 50' and 60', is concomitant with an apparently paradoxical large increase in the area of surface water, starting from the late 1980's. Spectacular for the two study cases of Agoufou and Ebang Mallam, for which time series covering the 1954-present period exist, this increase also reaches 98% between 1975 and 2002 for 92 ponds identified in central Gourma. Ponds with turbid waters and no aquatic vegetation are responsible for this increase, more pronounced to the north of the study zone. Possible causes of this change in surface water volume and regime are discussed based on differential changes in ponds dynamics related to the specifics in topography, soil texture and vegetation cover over the watershed. Changes in rain pattern and in ponds sedimentation are ruled out, and the

  11. Using Uav to Detect Shoreline Changes: Case Study - Pohranov Pond, Czech Republic

    NASA Astrophysics Data System (ADS)

    Čermáková, I.; Komárková, J.; Sedlák, P.

    2016-06-01

    The paper describes utilization of an unmanned aerial vehicle (UAV) for detection of changes of shorelines. UAV is used as a cheep and on-demand available possibility how to collect remotely sensed data. Its utilization is limited by legal regulations and weather conditions. Paper deals with utilization of UAV for monitoring small water area and particularly study of changes of shorelines. Study contains other methods of classification. After classification will be data processed for next calculations. Indices regarding shoreline changes are in the study also. In conclusion, study contains obtainment findings and encouragement for the future.

  12. Suitable Site Selection of Small Dams Using Geo-Spatial Technique: a Case Study of Dadu Tehsil, Sindh

    NASA Astrophysics Data System (ADS)

    Khalil, Zahid

    2016-07-01

    Decision making about identifying suitable sites for any project by considering different parameters, is difficult. Using GIS and Multi-Criteria Analysis (MCA) can make it easy for those projects. This technology has proved to be an efficient and adequate in acquiring the desired information. In this study, GIS and MCA were employed to identify the suitable sites for small dams in Dadu Tehsil, Sindh. The GIS software is used to create all the spatial parameters for the analysis. The parameters that derived are slope, drainage density, rainfall, land use / land cover, soil groups, Curve Number (CN) and runoff index with a spatial resolution of 30m. The data used for deriving above layers include 30 meter resolution SRTM DEM, Landsat 8 imagery, and rainfall from National Centre of Environment Prediction (NCEP) and soil data from World Harmonized Soil Data (WHSD). Land use/Land cover map is derived from Landsat 8 using supervised classification. Slope, drainage network and watershed are delineated by terrain processing of DEM. The Soil Conservation Services (SCS) method is implemented to estimate the surface runoff from the rainfall. Prior to this, SCS-CN grid is developed by integrating the soil and land use/land cover raster. These layers with some technical and ecological constraints are assigned weights on the basis of suitability criteria. The pair wise comparison method, also known as Analytical Hierarchy Process (AHP) is took into account as MCA for assigning weights on each decision element. All the parameters and group of parameters are integrated using weighted overlay in GIS environment to produce suitable sites for the Dams. The resultant layer is then classified into four classes namely, best suitable, suitable, moderate and less suitable. This study reveals a contribution to decision making about suitable sites analysis for small dams using geo-spatial data with minimal amount of ground data. This suitability maps can be helpful for water resource

  13. Radiological impact of Par Pond drawdown from liquid effluent pathways

    SciTech Connect

    Carlton, W.H.; Hamby, D.M.

    1991-10-25

    The water level of Par Pond has been lowered over the past several months to reduce the effects in the event of catastrophic dam failure while assessing the condition of the dam and determining if repairs are necessary. In lowering the level of Par Pond, 60 billion liters of water containing low levels of tritium and cesium-137 were discharged to several onsite streams. SRS surface streams flow to the Savannah River. An assessment made to determine the total amount of tritium and Cs-137 discharged and to estimate the consequences to downstream Savannah River users. It is estimated that a total of 160 curies of tritium were displaced from Par Pond to the Savannah River between June 28, 1991 and September 19, 1991. This release could hypothetically result in a maximum individual dose of 3. 2{times}10{sup {minus}4} mrem and a total (80-km and drinking water populations) population dose of 1.4{times}10{sup {minus}2} person-rem. Likewise, a maximum individual dose of 5.0{times}10{sup {minus}2} mrem and a total population dose of 1.7{times}10{sup {minus}1} person- rem are predicted as a result of an estimated 0.21 curies of Cs-137 being discharged from Par Pond to the Savannah River.

  14. Wintertime Emissions from Produced Water Ponds

    NASA Astrophysics Data System (ADS)

    Evans, J.; Lyman, S.; Mansfield, M. L.

    2013-12-01

    Every year oil and gas drilling in the U.S. generates billions of barrels of produced water (water brought to the surface during oil or gas production). Efficiently disposing of produced water presents a constant financial challenge for producers. The most noticeable disposal method in eastern Utah's Uintah Basin is the use of evaporation ponds. There are 427 acres of produced water ponds in the Uintah Basin, and these were used to evaporate more than 5 million barrels of produced water in 2012, 6% of all produced water in the Basin. Ozone concentrations exceeding EPA standards have been observed in the Uintah Basin during winter inversion conditions, with daily maximum 8 hour average concentrations at some research sites exceeding 150 parts per billion. Produced water contains ozone-forming volatile organic compounds (VOC) which escape into the atmosphere as the water is evaporated, potentially contributing to air quality problems. No peer-reviewed study of VOC emissions from produced water ponds has been reported, and filling this gap is essential for the development of accurate emissions inventories for the Uintah Basin and other air sheds with oil and gas production. Methane, carbon dioxide, and VOC emissions were measured at three separate pond facilities in the Uintah Basin in February and March of 2013 using a dynamic flux chamber. Pond emissions vary with meteorological conditions, so measurements of VOC emissions were collected during winter to obtain data relevant to periods of high ozone production. Much of the pond area at evaporation facilities was frozen during the study period, but areas that actively received water from trucks remained unfrozen. These areas accounted for 99.2% of total emissions but only 9.5% of the total pond area on average. Ice and snow on frozen ponds served as a cap, prohibiting VOC from being emitted into the atmosphere. Emissions of benzene, toluene, and other aromatic VOCs averaged over 150 mg m-2 h-1 from unfrozen pond

  15. Study on immobilization and migration of nuclide u in superficial soil of uranium tailings pond

    NASA Astrophysics Data System (ADS)

    Chang, Zhe; Zhou, Shukui

    2017-05-01

    The uranium tailings in southern China was used as the object of study to study the fixation and migration characteristics of nuclide U in shallow tailings. The results showed that the precipitation of tailings in the tailings soil was not linearly related to the depth during the acid rain leaching process. Tailings soil in the role of fixatives, when the lime as a fixative, the tailings of different soil uranium in 20 days after the re-precipitation. However, when lime and ammonium phosphate were used as fixing agents, the cumulative precipitation of U had a significant effect, and the migration of uranium was inhibited.

  16. Self-Reported Hearing Difficulties Among Adults With Normal Audiograms: The Beaver Dam Offspring Study

    PubMed Central

    Tremblay, Kelly L.; Pinto, Alex; Fischer, Mary E.; Klein, Barbara E. K.; Klein, Ronald; Levy, Sarah; Tweed, Ted S.; Cruickshanks, Karen J.

    2016-01-01

    Objective Clinicians encounter patients who report experiencing hearing difficulty (HD) even when audiometric thresholds fall within normal limits. When there is no evidence of audiometric hearing loss, it generates debate over possible biomedical and psychosocial etiologies. It is possible that self-reported HDs relate to variables within and/or outside the scope of audiology. The purpose of this study is to identify how often, on a population basis, people with normal audiometric thresholds self-report HD and to identify factors associated with such HDs. Design This was a cross-sectional investigation of participants in the Beaver Dam Offspring Study. HD was defined as a self-reported HD on a four-item scale despite having pure-tone audiometric thresholds within normal limits (<20 dB HL0.5, 1, 2, 3, 4, 6, 8 kHz bilaterally, at each frequency). Distortion product otoacoustic emissions and word-recognition performance in quiet and with competing messages were also analyzed. In addition to hearing assessments, relevant factors such as sociodemographic and lifestyle factors, environmental exposures, medical history, health-related quality of life, and symptoms of neurological disorders were also examined as possible risk factors. The Center for Epidemiological Studies-Depression was used to probe symptoms associated with depression, and the Medical Outcomes Study Short-Form 36 mental score was used to quantify psychological stress and social and role disability due to emotional problems. The Visual Function Questionnaire-25 and contrast sensitivity test were used to query vision difficulties. Results Of the 2783 participants, 686 participants had normal audiometric thresholds. An additional grouping variable was created based on the available scores of HD (four self-report questions), which reduced the total dataset to n = 682 (age range, 21–67 years). The percentage of individuals with normal audiometric thresholds who self-reported HD was 12.0% (82 of 682). The

  17. Studies on light intensity distribution inside an open pond photo-bioreactor.

    PubMed

    Pandey, Ramakant; Sahu, Akhilesh; K K, Vasumathi; M, Premalatha

    2015-08-01

    Light intensity profiles inside an open tank were studied using ANSYS Fluent. Experiments were performed by taking Scenedesmus arcuatus, green microalgae at three different concentrations under actual sunlight conditions. Absorption of light intensity at different depths was measured experimentally. The results generated from CFD simulations were compared with the experimental results and the cornet model. It has been found that there is a good agreement between the light intensity profile obtained from the CFD simulation and that calculated using the Cornet's model. Light intensity profiles at different depths were calculated using CFD simulation by varying the dimensions of the tank. The effect of wall reflectivity, diffuse fraction and scattering phase function on light profile in side open tank are also studied using CFD simulation.

  18. Local and landscape determinants of amphibian communities in urban ponds.

    PubMed

    Hamer, Andrew J; Parris, Kirsten M

    2011-03-01

    Urbanization is currently responsible for widespread declines of amphibian populations globally through the loss, isolation, and degradation of habitat. However, it is not clear how urbanization affects amphibian communities at both local (pond) and landscape scales. We assessed the breeding distribution of frogs in ponds along an urban-rural gradient in Greater Melbourne, Australia, and examined community relationships with habitat quality and landscape context. We sampled frog larvae at 65 ponds on four separate occasions and collected data on local pond and landscape variables. Using Bayesian Poisson regression modeling we found that species richness decreased at ponds surrounded by high densities of human residents and at ponds with high water conductivity, whereas species richness increased substantially at ponds surrounded by a high proportion of green open space. Ordination of individual species presence-absence data by canonical correspondence analysis largely confirmed these findings. Ordination also highlighted the negative influences of pond shading and density of predatory fish, and the positive influence of aquatic vegetation, on community composition. Individual species' responses to urbanization varied. Urbanization had strong negative effects on species that were associated with well-vegetated, sunny, fish-free ponds. Our study highlights the importance of strategic management actions in urban landscapes to improve terrestrial habitat and connectivity around ponds and other wetlands, and local management actions to improve water quality, remove predatory fish, and plant aquatic vegetation at breeding sites.

  19. Case study analysis of the legal and institutional obstacles and incentives to the development of the hydroelectric power at the Maxwell locks and dam, Pennsylvania

    SciTech Connect

    None,

    1980-05-01

    The legal, institutional and financial obstacles, and incentives to the development of hydroelectric power at the Maxwell locks and dam on the Monongahela River are analyzed. The study is one of five studies prepared by the Energy Law Institute pursuant to a contract with the National Conference of State Legislators. Each of the five studies views dam development by a different category of developer. These categories include a municipality, a public utility, a state, a private developer, and a cooperative. The Maxwell case study concerns potential development by Allegheny Electric Cooperative. Thus, the analysis of obstacles and incentives is focused on those factors which have particular impact on a cooperative. Subjects covered include a description of the site; developer description; the feasibility study; the economic feasibility; financing; Federal licensing by FERC; state licensing; local interest and requirements; the effect of locks and dam operation by the Army Corp of Engineers; and power marketing.

  20. Elaboration of A Numerical Model For The Study of The Dam Rupture Wave Displacement

    NASA Astrophysics Data System (ADS)

    Iddir, R.; Laradi, N.

    The essential purpose assigned to this present research is the contribution to the devel- opment of a model numeric two-dimensional permitting the simulation of a transient flow to free surface, quickly varied, resulting of a total and instantaneous rupture of a dam in a rectangular channel. For that to make, we present in a first section, the representative mathematical model of this flow, based on Saint Venat equations two- dimensional. An algorithm in finite differences is developed then to resolve this system of equations. The algorithm for needs of our research is to fractional step, based on the numeric diagram of Mac Cormack. During this simulation, we put in evidence the evolution in the time, the height and the speed of the flow in different positions, and this until drains it of the dam. We are also interested to the survey of the certain param- eter influence on the flow as the slope of the bottom, the roughness of Manning and the initial height of water in the reservoir. Finally to validate and to test performances of the model developed, we did several applications in the second section, then compared results gotten to the experimental and numeric results.

  1. Olive mill wastewater evaporation management using PCA method Case study of natural degradation in stabilization ponds (Sfax, Tunisia).

    PubMed

    Jarboui, Raja; Sellami, Fatma; Azri, Chafai; Gharsallah, Néji; Ammar, Emna

    2010-04-15

    Olive mill wastewater (OMW) evaporation ponds management was investigated in five serial evaporation open-air multiponds of 50 ha located in Sfax (Tunisia). Physico-chemical parameters and microbial flora evolution were considered. Empirical models describing the OMW characteristic changes with the operation time were established and Principal Component Analysis (PCA) described the correlation between physico-chemical and biological parameters. COD, BOD, total solids, polyphenols and electrical conductivity exhibited first-order models. Four groups exhibited high correlations. The first included temperature, density, COD, TSS, TS, BOD, VS, TOC, TKN, polyphenols and minerals. The second group was made up of yeasts and moulds. The third group was established with phenolic compounds, total sugars, fats, total phosphorous, NH(4)(+) and pH. The fourth group was constituted by exclusively aerobic bacteria. Bacterial-growth toxic effect was exhibited by high organic load, ash content and polyphenols, whereas moulds and yeasts were more adapted to OMW. During the storage, all the third group parameter values decreased and were inversely related to the others. In the last pond, COD, BOD, TS and TSS rates were reduced by 40%, 50%, 50% and 75% respectively. The evaporation and the biological activity were the main processes acting, predicting the OMW behavior during evaporation in air-open ponds.

  2. Combined electron microscopy and vibrational spectroscopy study of corroded Magnox sludge from a legacy spent nuclear fuel storage pond

    NASA Astrophysics Data System (ADS)

    Gregson, Colin R.; Goddard, David T.; Sarsfield, Mark J.; Taylor, Robin J.

    2011-05-01

    Samples of filtered particulates and sludges, formed from corroding magnesium alloy clad uranium metal ("Magnox") fuel elements, collected from one of the legacy nuclear fuel storage ponds located at Sellafield (UK) were investigated by Environmental Scanning Electron Microscopy with Energy Dispersive X-Ray analysis (ESEM/EDX), micro-Raman spectroscopy and Fourier transform infra-red spectroscopy (FT-IR). ESEM imaging confirmed the dominant morphology to be clusters of interlocking platelets typical of brucite (Mg(OH) 2). EDX analysis was suggestive of some conversion to the related phase, hydrotalcite (Mg 6Al 2(CO 3)(OH) 16·4H 2O), due to elevated levels of Al associated with Mg. Other apparent morphologies were less commonly observed including flaky sheets, consistent with earlier stages of Magnox alloy corrosion. In a few specific cases, rods were also observed suggestive of some conversion to Mg-hydroxycarbonate phases. Discrete phases rich in U were also identified. Fluorescence in the Raman spectroscopy also indicated surface coatings of organic macromolecules and iron sulphide on hematite containing particles, attributed to microbial activity within the open air pond. Some specific differences in the solid phases between pond areas with differing conditions were apparent.

  3. Saltless solar pond

    NASA Technical Reports Server (NTRS)

    Lin, E. I. H. (Inventor)

    1984-01-01

    A solar pond adapted for efficiently trapping and storing radiant solar energy without the use of a salt concentration gradient in the pond is disclosed. A body of water which may be fresh, saline, relatively clear or turbid, is substantially covered by a plurality of floating honeycomb panels. The honeycomb panels are made of a material such as glass which is pervious to short wave solar radiation but impervious to infrared radiation. Each honeycomb panel includes a multitude of honeycomb cells. The honeycomb panels are divided into the elongated honeycomb cells by a multitude of intermediate plates disposed between a bottom plate and top plate of the panel. The solar pond is well suited for providing hot water of approximately 85 to 90 C temperature for direct heating applications, and for electrical power generation.

  4. Saltless solar pond

    NASA Astrophysics Data System (ADS)

    Lin, E. I. H.

    1984-09-01

    A solar pond adapted for efficiently trapping and storing radiant solar energy without the use of a salt concentration gradient in the pond is disclosed. A body of water which may be fresh, saline, relatively clear or turbid, is substantially covered by a plurality of floating honeycomb panels. The honeycomb panels are made of a material such as glass which is pervious to short wave solar radiation but impervious to infrared radiation. Each honeycomb panel includes a multitude of honeycomb cells. The honeycomb panels are divided into the elongated honeycomb cells by a multitude of intermediate plates disposed between a bottom plate and top plate of the panel. The solar pond is well suited for providing hot water of approximately 85 to 90 C temperature for direct heating applications, and for electrical power generation.

  5. Treatment of piggery wastes in waste stabilization ponds.

    PubMed

    Estrada, V E E; Hernández, D E A

    2002-01-01

    The piggery industry produces high effluent loads. This is due to the high concentration of animals kept in a confined space, foods with high protein content that are not well assimilated by the animals, and poor on-farm water management. In this study, we present the characteristics, design, site selection, soil study, and the construction of a pilot pond system for a family farm located in a warm climate area. The design includes a solids sedimentation phase, an anaerobic pond, a facultative pond and three maturation ponds. Once the system had reached steady state, the organic and bacterial kinetic constants were determined for each pond. The control parameters were determined and the dissolved oxygen and removal efficiency profiles were obtained. The results indicate that the effluent from the second maturation pond complies with the Official Mexican Standard for reuse in agriculture ("1000 FC/100 ml).

  6. National Dam Inspection Program. Lower Hemlock Dam (NDI-ID Number PA-00756, DER-ID Number 52-117) Delaware River Basin, Pike County, Pennsylvania. Phase I Inspection Report.

    DTIC Science & Technology

    1980-06-01

    Spillway crest (Elev. 1432.0) 23.1 -3- G. Dam Refer to Plates III & IV in Appendix E for plan and section. Type: Earth embankment with concrete core...visual inspection check list and sketches of the general plan and profile of the dam, as surveyed during the inspection, are presented in Appendix A...Pecks Pond, Pa. See Plate II, Appendix E CONSTRUCTION HISTORY No records. GENERAL PLAN OF DAM Plate III, Appendix E. TYPICAL SECTIONS Plate IV, Appendix

  7. 50. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- DAM CONCRETE -- GENERAL ARRANGEMENT -- SECTION AND ELEVATIONS. M-L 26(R) 40/3 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  8. 49. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- DAM CONCRETE -- TYPICAL PIER ISOMETRIC. M-L 26(R) 40/1 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  9. CRIB DAM, LOOKING ALONG DAM FROM WEST ABUTMENT, SHOWING PLANK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CRIB DAM, LOOKING ALONG DAM FROM WEST ABUTMENT, SHOWING PLANK SHEATHING IN FOREGROUND. VIEW TO EAST - Kachess Dam, 1904 Cascade Canal Company Crib Dam, Kachess River, 1.5 miles north of Interstate 90, Easton, Kittitas County, WA

  10. Managed aquifer recharge by a check dam to improve the quality of fluoride-rich groundwater: a case study from southern India.

    PubMed

    Gowrisankar, G; Jagadeshan, G; Elango, L

    2017-04-01

    In many regions around the globe, including India, degradation in the quality of groundwater is of great concern. The objective of this investigation is to determine the effect of recharge from a check dam on quality of groundwater in a region of Krishnagiri District of Tamil Nadu State, India. For this study, water samples from 15 wells were periodically obtained and analysed for major ions and fluoride concentrations. The amount of major ions present in groundwater was compared with the drinking water guideline values of the Bureau of Indian Standards. With respect to the sodium and fluoride concentrations, 38% of groundwater samples collected was not suitable for direct use as drinking water. Suitability of water for agricultural use was determined considering the electrical conductivity, sodium adsorption ratio, sodium percentage, permeability index, Wilcox and United States Salinity Laboratory diagrams. The influence of freshwater recharge from the dam is evident as the groundwater in wells nearer to the check dam was suitable for both irrigation and domestic purposes. However, the groundwater away from the dam had a high ionic composition. This study demonstrated that in other fluoride-affected areas, the concentration can be reduced by dilution with the construction of check dams as a measure of managed aquifer recharge.

  11. Summary of juvenile salmonid passage and survival at McNary Dam-Acoustic survival studies, 2006-09

    USGS Publications Warehouse

    Adams, Noah S.; Evans, Scott D.

    2011-01-01

    Passage and survival data were collected at McNary Dam between 2006 and 2009. These data have provided critical information for resource managers to implement structural and operational changes designed to improve the survival of juvenile salmonids as they migrate past the dam. Given the importance of these annual studies, the primary objectives of this report were to summarize the findings of these annual studies to ensure that passage and survival metrics are consistently calculated and reported across all years and to consolidate this information in a single document, thereby making it easier to reference. It is worth noting that this report does not contain all the information from all the annual reports. The intent of this report was to summarize the key findings from multiple years of research. The reader is encouraged to reference the annual reports if more detailed information is needed. Chapter 1 summarizes existing behavior, passage, and survival results for fish released 10 rkm upstream of McNary Dam and from the McNary Dam tailrace during 2006-09. Chapter 2 summarizes existing behavior, passage, and survival results for fish released in the mid-Columbia River and detected at McNary Dam during 2006-09. Results from 2006 indicated that higher spill discharge generally resulted in higher fish passage through spill, and in turn, higher fish survival through the entire dam. Within the spillway, passage effectiveness was highest for the south spill bays, adjacent to the powerhouse. Increased passage in this area, combined with detailed 3-dimensional approach paths, aided in the design and location of the temporary spillway weirs (TSWs) at McNary Dam prior to the 2007 migration of juvenile salmonids. During the 2007 study, the TSWs were tested under two spill treatments during the spring and summer: a "2006 Modified spill," and a "2007 test spill." In the spring, slightly higher discharge through spill bays 14-17 was the primary difference between the spill

  12. Falmouth pond watchers: Water quality monitoring of Falmouth's coastal ponds. Report from the 1992 season

    SciTech Connect

    Howes, B.L.; Goehringer, D.D.

    1993-04-01

    1992 has seen a significant expansion in the focus of the Pond Watchers program. The long-term, high quality data base for the ponds is now enabling more emphasis on the ecological management and remediation aspects of the study, the ultimate goal of the program. Overall, 1992 saw only slight variation in the water quality conditions of Oyster, Little, Green, Great and Bournes Ponds from previous years, with a declining trend for Green Pond and small improvements in lower Great and Bournes Ponds. However, Oyster Pond showed a potentially significant improvement in bottom water oxygen conditions which suggests a new management direction for this system. All of the ponds continue to exhibit high nutrient levels and periodic bottom water oxygen depletion, especially in their upper reaches, and all stations exceed the nutrient levels specified by the Nutrient Overlay Bylaw. In contrast, the first year measurements in West Falmouth Harbor indicate high levels of water quality, although the inner reaches of the harbor do exceed those levels specified by the Bylaw.

  13. Particle Clogging in Filter Media of Embankment Dams: A Numerical and Experimental Study

    NASA Astrophysics Data System (ADS)

    Antoun, T.; Kanarska, Y.; Ezzedine, S. M.; Lomov, I.; Glascoe, L. G.; Smith, J.; Hall, R. L.; Woodson, S. C.

    2013-12-01

    The safety of dam structures requires the characterization of the granular filter ability to capture fine-soil particles and prevent erosion failure in the event of an interfacial dislocation. Granular filters are one of the most important protective design elements of large embankment dams. In case of cracking and erosion, if the filter is capable of retaining the eroded fine particles, then the crack will seal and the dam safety will be ensured. Here we develop and apply a numerical tool to thoroughly investigate the migration of fines in granular filters at the grain scale. The numerical code solves the incompressible Navier-Stokes equations and uses a Lagrange multiplier technique which enforces the correct in-domain computational boundary conditions inside and on the boundary of the particles. The numerical code is validated to experiments conducted at the US Army Corps of Engineering and Research Development Center (ERDC). These laboratory experiments on soil transport and trapping in granular media are performed in constant-head flow chamber filled with the filter media. Numerical solutions are compared to experimentally measured flow rates, pressure changes and base particle distributions in the filter layer and show good qualitative and quantitative agreement. To further the understanding of the soil transport in granular filters, we investigated the sensitivity of the particle clogging mechanism to various parameters such as particle size ratio, the magnitude of hydraulic gradient, particle concentration, and grain-to-grain contact properties. We found that for intermediate particle size ratios, the high flow rates and low friction lead to deeper intrusion (or erosion) depths. We also found that the damage tends to be shallower and less severe with decreasing flow rate, increasing friction and concentration of suspended particles. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under

  14. Evaluation of solar pond performance

    SciTech Connect

    Wittenberg, L.J.

    1980-01-01

    The City of Miamisburg, Ohio, constructed during 1978 a large, salt-gradient solar pond as part of its community park development project. The thermal energy stored in the pond is being used to heat an outdoor swimming pool in the summer and an adjacent recreational building during part of the winter. This solar pond, which occupies an area of 2020 m/sup 2/ (22,000 sq. ft.), was designed from experience obtained at smaller research ponds located at Ohio State University, the University of New Mexico and similar ponds operated in Israel. During the summer of 1979, the initial heat (40,000 kWh, 136 million Btu) was withdrawn from the solar pond to heat the outdoor swimming pool. All of the data collection systems were installed and functioned as designed so that operational data were obtained. The observed performance of the pond was compared with several of the predicted models for this type of pond. (MHR)

  15. Post Falls Dam stabilization

    SciTech Connect

    Gorny, R.H.; Gibson, J.Z.

    1995-12-31

    The stability of Washington Water Power`s (WWP) Middle Channel and South Channel Dams at Post Falls, Idaho, were evaluated as required by the Federal Energy Regulatory Commission (FERC) and did not meet guideline stability criteria under Probable Maximum Flood (PMF) loading. This paper describes the stability analysis, stabilization design, design parameters, construction of the anchors, and compares the design and as-built conditions. Value engineering was used to select the optimal stabilization measure. Constructibility, cost, and schedule were major considerations. The value engineering study evaluated 41 potential stabilization alternatives, selected post tensioning, and used scheduling criteria to optimize the design. Access considerations required the installation of five 47 strand, 7400 kN (1645{sup k}) anchors in the Middle Dam, and installation of six anchors with different capacities anchors in the South Channel Dam. The Washington Water Power - Black & Veatch team used value engineering, contractor prequalification, resident engineering services provided by the engineer, and strong construction support provided by the Owner to successfully complete the project on a very tight schedule.

  16. Truscott Brine Lake solar-pond system conceptual design

    NASA Astrophysics Data System (ADS)

    Leboeuf, C. M.; May, E. K.

    1982-08-01

    Discussed is a conceptual design study for a system of electricity-producing salt-gradient solar ponds that will provide power to a chloride control project under construction near Truscott, Tex. The chloride control project comprises a 1200-ha (3000-acre) brine impoundment lake to which brine will be pumped from several salty sources in the Wichita River basin. The solar ponds are formed by natural evaporation of the briny water pumped to Truscott. Heat is extraced from the solar ponds and used to drive organic Rankine-cycle generators. Ponds were sized to provide the pumping needs of the chloride control project and the maintenance requirements of the solar ponds. The system includes six solar pond modules for a total area of 63.1 ha, and produces 1290 kW of base load electricity. Although sized for continuous power production, alternative operating scenarios involving production of peak power for shorter durations were also examined.

  17. Juvenile Radio-Tag Study: Lower Granite Dam, 1985-1986 Final Report.

    SciTech Connect

    Giorgi, Albert E.

    1988-03-01

    A prototype juvenile radio-tag system was developed and tested by the National Marine Fisheries Services (NMFS) and Bonneville Power Administration (BPA) at John Day Dam in 1984. Results indicated that the system could provide acceptable estimates of powerhouse and spillway passage. Research in 1986 continued testing of the tag system to further define its application and limitations. Field work included releases in the forebay and tailrace under a no-spill environment and testing of new systems to improve tag detection. Laboratory tests included the response of the tag in hostile environmental conditions (spillway passage) and the effects of the radio tag on fish buoyancy compensation. This report provides results of the work along with a summarization of the combined 1985--86 field and assumption testing. 12 refs., 10 figs., 8 tabs.

  18. The dam breakage of Baia Mare??a pilot study of magnetic screening

    NASA Astrophysics Data System (ADS)

    Wehland, F.; Panaiotu, C.; Appel, E.; Hoffmann, V.; Jordanova, D.; Jordanova, N.; Denut, I.

    Magnetic screening in the area of Baia Mare (Romania) was carried out in June 2000 in order to detect the degree of environmental pollution and to test the applicability of this method in this area. With a long tradition of mining activities, a gradual pollution of soil, air and rivers took place continuously in addition to smaller accidents in this area until the dam breakage on the 30.1.2000. During this accident, about 100,000 m 3 of mud containing cyanide and heavy metals leaked out and moved over fields and through a village into the river system of Lapûs, Someş, Tisza and Danube. Initial magnetic monitoring carried out during the translocation of the polluted waters along the Bulgarian part of the Danube revealed the effectiveness of the method for a proper and fast identification of pollution both in time and space even at remote distances from the source. For the later pilot project magnetic ( χ) screening was performed using a portable Bartington MS2 kappameter with a D-loop sensor. In addition fine-grained material (<0.5 mm) was sampled from the fields and river sediments and measured in the laboratory using a MS2 B-sensor. The results of the collected samples show a clear decrease in χ with increasing distance from the dams and mining areas in a regional and local scale, while the results gained by the MS2-D strongly depend on the nature of the ground. The dynamic geological setting around Baia Mare (fluvial sediments and valley fills), produces a heterogeneous background signal. A continuous monitoring system controlling the basic conditions could overcome these limitations.

  19. National Dam Safety Program. Potake Lake Dam (Inventory Number N.Y. 970), Passaic River Basin, Lower Hudson River Area, Rockland County, New York. Phase I Inspection Report,

    DTIC Science & Technology

    1981-08-14

    Highlands are characterized by strong topo- graphic linearity in which the majority of the ridges and valleys follow the northwest-southwest strike of the...I I POTAKE -N- ~- POND DAM DeSe 4 - 0 .4 u 4e S / /4 ~ ~ i~ ;3Mi -N. ,f c ,,--POAK PO DAM’ -ce - a-6 ~ - ~~-T- - ’e,-- ~~~ TRONEDM .7-L[(74 . ’V Shppr

  20. National Dam Safety Program. Unimin Tailings Dam (Inventory Number VA 06918), Potomac River Basin, Frederick County, Commonwealth of Virginia. Phase I Inspection Report.

    DTIC Science & Technology

    1981-01-01

    and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Phase I Inspection Report Final National Dam Safety Program 6. PERFORMING ORG. REPORT NUMBER - 7...spillway riser pipe approximately four feet below the crest of the riser pipe (Photo 1). This valve is used during periods ’Facing downstream. NAME OF DAM...during periods of low flow to lower the level in the reservoir approximately 4 feet in order to maintain the water supply into the fresh water pond located

  1. The Impact of Dam-Reservoir-Foundation Interaction on Nonlinear Response of Concrete Gravity Dams

    SciTech Connect

    Amini, Ali Reza; Motamedi, Mohammad Hossein; Ghaemian, Mohsen

    2008-07-08

    To study the impact of dam-reservoir-foundation interaction on nonlinear response of concrete gravity dams, a two-dimensional finite element model of a concrete gravity dam including the dam body, a part of its foundation and a part of the reservoir was made. In addition, the proper boundary conditions were used in both reservoir and foundation in order to absorb the energy of outgoing waves at the far end boundaries. Using the finite element method and smeared crack approach, some different seismic nonlinear analyses were done and finally, we came to a conclusion that the consideration of dam-reservoir-foundation interaction in nonlinear analysis of concrete dams is of great importance, because from the performance point of view, this interaction significantly improves the nonlinear response of concrete dams.

  2. Focusing on dam safety

    SciTech Connect

    Lagassa, G.

    1993-01-01

    With increased relicensing activity and a federal emphasis on safety, dam repair and refurbishment is a growing business. Providers of goods and services are gearing up to meet the dam repair and rehabilitation needs that result.

  3. Study of bacteriophage T4-encoded Dam DNA (adenine-N6)-methyltransferase binding with substrates by rapid laser UV cross-linking.

    PubMed

    Evdokimov, Alexey A; Sclavi, Bianca; Zinoviev, Victor V; Malygin, Ernst G; Hattman, Stanley; Buckle, Malcolm

    2007-09-07

    DNA methyltransferases of the Dam family (including bacteriophage T4-encoded Dam DNA (adenine-N(6))-methyltransferase (T4Dam)) catalyze methyl group transfer from S-adenosyl-L-methionine (AdoMet), producing S-adenosyl-L-homocysteine (AdoHcy) and methylated adenine residues in palindromic GATC sequences. In this study, we describe the application of direct (i.e. no exogenous cross-linking reagents) laser UV cross-linking as a universal non-perturbing approach for studying the characteristics of T4Dam binding with substrates in the equilibrium and transient modes of interaction. UV irradiation of the enzyme.substrate complexes using an Nd(3+):yttrium aluminum garnet laser at 266 nm resulted in up to 3 and >15% yields of direct T4Dam cross-linking to DNA and AdoMet, respectively. Consequently, we were able to measure equilibrium constants and dissociation rates for enzyme.substrate complexes. In particular, we demonstrate that both reaction substrates, specific DNA and AdoMet (or product AdoHcy), stabilized the ternary complex. The improved substrate affinity for the enzyme in the ternary complex significantly reduced dissociation rates (up to 2 orders of magnitude). Several of the parameters obtained (such as dissociation rate constants for the binary T4Dam.AdoMet complex and for enzyme complexes with a nonfluorescent hemimethylated DNA duplex) were previously inaccessible by other means. However, where possible, the results of laser UV cross-linking were compared with those of fluorescence analysis. Our study suggests that rapid laser UV cross-linking efficiently complements standard DNA methyltransferase-related tools and is a method of choice to probe enzyme-substrate interactions in cases in which data cannot be acquired by other means.

  4. The Little School Pond

    ERIC Educational Resources Information Center

    Rawitscher-Kunkel, Erika

    1973-01-01

    A small pond in a schoolyard provided year-round biological activities for children. As seasons changed, concepts and life relations also changed. Besides microscopic organisms in water, children learned about microscopic algae, detritus, and food chains. Concepts of predator-prey relationships and of ecosystems were successfully developed. (PS)

  5. The Little School Pond

    ERIC Educational Resources Information Center

    Rawitscher-Kunkel, Erika

    1973-01-01

    A small pond in a schoolyard provided year-round biological activities for children. As seasons changed, concepts and life relations also changed. Besides microscopic organisms in water, children learned about microscopic algae, detritus, and food chains. Concepts of predator-prey relationships and of ecosystems were successfully developed. (PS)

  6. Partitioned pond aquaculture systems

    USDA-ARS?s Scientific Manuscript database

    World aquaculture is dominated by the use of simple earthen ponds in which suitable water quality is maintained by photosynthetic processes. Relying upon sunlight to maintain water quality offers the lowest cost and most sustainable approach to fish or shellfish production, which explains the popula...

  7. Water quality, phytoplankton and zooplankton of Par Pond and Pond B. Volume 1. Water quality. Final report, January 1984-June 1985

    SciTech Connect

    Chimney, M.J.; Cody, W.R.; Starkel, W.M.

    1985-08-01

    The objectives of this study were to: (1) characterize the biological communities and environmental conditions in Par Pond and pond B; (2) assess the impact and significance of entrainment losses of plankton at the Par Pond pumphouse; (3) assess the impact of heated discharge on the biotic communities throughout the reservior; and (4) help determine if Par Pond maintains an indigenous balanced biological community as defined in state and federal regulations.

  8. Quality control summary report for the RFI/RI assessment of the submerged sediment core samples taken at Par Pond, Pond C, and L-Lake

    SciTech Connect

    Koch, J. II

    1996-12-01

    This report presents a summary of the sediment characterization performed under the direction of the Westinghouse Savannah River Company`s (WSRC) Environmental Protection Department/Environmental Monitoring Section (EPD/EMS) in support of Par Pond, Pond C, and L- Lake. This characterization will be a screening study and will enable the Environmental Sciences Section (ESS) to develop a defensible contaminants of concern list for more extensive characterization of the Par Pond, Pond C, and L-Lake.

  9. Effect of climate change on stormwater runoff characteristics and treatment efficiencies of stormwater retention ponds: a case study from Denmark using TSS and Cu as indicator pollutants.

    PubMed

    Sharma, Anitha Kumari; Vezzaro, Luca; Birch, Heidi; Arnbjerg-Nielsen, Karsten; Mikkelsen, Peter Steen

    2016-01-01

    This study investigated the potential effect of climate changes on stormwater pollution runoff characteristics and the treatment efficiency of a stormwater retention pond in a 95 ha catchment in Denmark. An integrated dynamic stormwater runoff quality and treatment model was used to simulate two scenarios: one representing the current climate and another representing a future climate scenario with increased intensity of extreme rainfall events and longer dry weather periods. 100-year long high-resolution rainfall time series downscaled from regional climate model projections were used as input. The collected data showed that total suspended solids (TSS) and total copper (Cu) concentrations in stormwater runoff were related to flow, rainfall intensity and antecedent dry period. Extreme peak intensities resulted in high particulate concentrations and high loads but did not affect dissolved Cu concentrations. The future climate simulations showed an increased frequency of higher flows and increased total concentrations discharged from the catchment. The effect on the outlet from the pond was an increase in the total concentrations (TSS and Cu), whereas no major effect was observed on dissolved Cu concentrations. Similar results are expected for other particle bound pollutants including metals and slowly biodegradable organic substances such as PAH. Acute toxicity impacts to downstream surface waters seem to be only slightly affected. A minor increase in yearly loads of sediments and particle-bound pollutants is expected, mainly caused by large events disrupting the settling process. This may be important to consider for the many stormwater retention ponds existing in Denmark and across the world.

  10. Hoover Dam Learning Packet.

    ERIC Educational Resources Information Center

    Bureau of Reclamation (Dept. of Interior), Washington, DC.

    This learning packet provides background information about Hoover Dam (Nevada) and the surrounding area. Since the dam was built at the height of the Depression in 1931, people came from all over the country to work on it. Because of Hoover Dam, the Colorado River was controlled for the first time in history and farmers in Nevada, California, and…

  11. Retinal thickness measured by spectral-domain optical coherence tomography in eyes without retinal abnormalities: the Beaver Dam Eye Study.

    PubMed

    Myers, Chelsea E; Klein, Barbara E K; Meuer, Stacy M; Swift, Maria K; Chandler, Charles S; Huang, Yijun; Gangaputra, Sapna; Pak, Jeong W; Danis, Ronald P; Klein, Ronald

    2015-03-01

    To examine relationships of age, sex, and systemic and ocular conditions with retinal thickness measured by spectral-domain ocular coherence tomography (SD OCT) in participants without retinal disease. Longitudinal study. setting: Population-based cohort. study population: Persons aged 43-86 years living in Beaver Dam, Wisconsin in 1988-1990. observation procedures: Retinal thickness was measured via SD OCT at the Beaver Dam Eye Study examination in 2008-2010. Retinal disease was determined by ophthalmoscopy, fundus photography, or SD OCT. main outcome measures: Retinal thickness from the inner limiting membrane to the Bruch membrane. The retina was thickest in the inner circle (mean 334.5 μm) and thinnest in the center subfield (285.4 μm). Mean retinal thickness decreased with age in the inner circle (P < .0001) and outer circle (P < .0001). Adjusting for age, eyes in men had thicker retinas than eyes in women in the center subfield (P < .001) and inner circle (P < .001). Sex, axial length/corneal curvature ratio, and peak expiratory flow rate were associated with center subfield thickness. Sex and peak expiratory flow rate were associated with retinal thickness in the inner circle. Alcohol consumption, age, axial length/corneal curvature ratio, cataract surgery, ocular perfusion pressure, and peak expiratory flow rate were associated with retinal thickness in the outer circle. This study provides data for retinal thickness measures in eyes of individuals aged 63 years and older without retinal disease. This information may be useful for clinical trials involving the effects of interventions on retinal thickness and for comparisons with specific retinal diseases affecting the macula. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. A model of the refreezing of melt ponds

    NASA Astrophysics Data System (ADS)

    Flocco, D.; Feltham, D. L.; Schroeder, D.

    2012-12-01

    Melt ponds form on Arctic sea ice during the melting season and their presence affects the heat and mass balance of the ice cover. Towards the end of the melt season melt ponds cover up to 50% of the sea ice area decreasing the value of the surface albedo by up to 20%. The dramatic impact of melt ponds on the albedo feedback mechanism for sea ice melt has been demonstrated in previous studies. Here, we focus on the refreezing of melt ponds. As the ponds freeze from above, they gradually release latent heat that inhibits basal ice growth. The refreezing process can take up to three months. Within the ASBO (Arctic Synoptic Basin-wide Observations) project we have developed a model of refreezing melt ponds that uses mushy layer theory to describe the sea ice and takes account of the presence of salt in the refreezing melt pond. We use this model to investigate the rate at which melt ponds refreeze, releasing latent heat, and their impact on sea ice growth. Model results are compared with in situ data collected by Ice Mass Balance buoys in the Arctic. Furthermore we will give an estimate of the impact of the melt pond presence on sea ice growth in the Arctic basin.

  13. Minimizing contamination hazards to waterbirds using agricultural drainage evaporation ponds

    NASA Astrophysics Data System (ADS)

    Bradford, David F.; Smith, Lynda A.; Drezner, Deborah S.; Shoemaker, J. David

    1991-11-01

    In much of the San Joaquin Valley, California, USA, inadequate drainage of applied irrigation water and accumulating salts in the soil have necessitated the installation of subsurface tile drainage systems to preserve crop productivity. At present, these subsurface drainage waters are disposed of by means of evaporation ponds or discharges into the San Joaquin River. Unfortunately, most of these agricultural drainage waters contain high concentrations of salts and naturally occurring trace elements, such as selenium, and recent evidence indicates that substantial numbers of waterbirds are exposed to contamination by selenium in the evaporation ponds. In order to avoid, minimize, or mitigate the adverse impacts on wildlife using the ponds, alternative pond management methods must be identified and evaluated for implementation. A number of methods have the potential to be cost-effective in significantly reducing the contamination hazard to birds using agricultural evaporation ponds. Twenty general methods were evaluated in this study, and four methods are recommended for implementation: remove levee vegetation, remove windbreaks, deepen the ponds, and haze birds. A number of other methods are recommended for further consideration because they appear to have good prospects for reducing the contamination hazard: steepen interior levee slopes, apply herbicides and insecticides, place netting on pond shorelines, and provide freshwater habitat adjacent to evaporation ponds. It may be necessary to use a combination of methods to effectively control selenium contamination of aquatic birds because it is unlikely that a single affordable pond management method will be able to entirely eliminate the contamination hazard.

  14. Depositional Model for a Beaver Pond Complex in a Piedmont Stream Valley

    NASA Astrophysics Data System (ADS)

    Rachide, S. P.; Diemer, J. A.

    2016-12-01

    The North American beaver (Castor canadensis) often construct closely-spaced ponds on suitable sections of streams. Over time avulsive processes form an intricate network of shallow anabranching streams that connect a multitude of ponds, referred to here as a beaver pond complex (BPC). According to Polvi and Wohl (2012), BPCs evolve through four stages. Their model, resulting from the study of an alpine stream dominated by meltwater, focused on changes in valley planform, increased channel complexity, and the effects of floodplain sediment storage during the growth of a BPC. A revised depositional model for a multi-generation BPC is presented here, based on data collected at Mill Creek, in the Piedmont of North Carolina. The field data, comprising geolocated maps, cores and probes, were collected between March 2011 and October 2014 and were supplemented by 12 aerial images of the field area taken from January 1993 to October 2014. The revised BPC depositional model comprises several stages of development that include initial beaver occupation, followed by an interval of fast-paced pond creation and increasing channel complexity, a stage of slowing growth of the BPC, followed by cycles of dam breaching and repair, and an abandonment phase. An additional stage may include later reoccupation of an abandoned BPC to produce a multi-generation BPC. The areas affected by, and durations of, these stages are likely dictated by several variables including: geologic controls, local climate, hydrologic regime, beaver population size, and resource availability. Rare large precipitation events that led to the breaching of dams were likely the most impactful variable in the evolution of the Mill Creek BPC. Field observations indicate that beaching events affected the Mill Creek BPC more frequently than could be inferred from the 12 aerial images of the site. Therefore, aerial imagery should be used in conjunction with field-based investigations in order to more accurately

  15. Topics on distance correlation, feature screening and lifetime expectancy with application to Beaver Dam eye study data

    NASA Astrophysics Data System (ADS)

    Kong, Jing

    This thesis includes 4 pieces of work. In Chapter 1, we present the work with a method for examining mortality as it is seen to run in families, and lifestyle factors that are also seen to run in families, in a subpopulation of the Beaver Dam Eye Study that has died by 2011. We find significant distance correlations between death ages, lifestyle factors, and family relationships. Considering only sib pairs compared to unrelated persons, distance correlation between siblings and mortality is, not surprisingly, stronger than that between more distantly related family members and mortality. Chapter 2 introduces a feature screening procedure with the use of distance correlation and covariance. We demonstrate a property for distance covariance, which is incorporated in a novel feature screening procedure based on distance correlation as a stopping criterion. The approach is further implemented to two real examples, namely the famous small round blue cell tumors data and the Cancer Genome Atlas ovarian cancer data Chapter 3 pays attention to the right censored human longevity data and the estimation of lifetime expectancy. We propose a general framework of backward multiple imputation for estimating the conditional lifetime expectancy function and the variance of the estimator in the right censoring setting and prove the properties of the estimator. In addition, we apply the method to the Beaver Dam eye study data to study human longevity, where the expected human lifetime are modeled with smoothing spline ANOVA based on the covariates including baseline age, gender, lifestyle factors and disease variables. Chapter 4 compares two imputation methods for right censored data, namely the famous Buckley-James estimator and the backward imputation method proposed in Chapter 3 and shows that backward imputation method is less biased and more robust with heterogeneity.

  16. Dam Mycobacterium avium subspecies paratuberculosis (MAP) infection status does not predetermine calves for future shedding when raised in a contaminated environment: a cohort study.

    PubMed

    Eisenberg, Susanne W F; Rutten, Victor P M G; Koets, Ad P

    2015-06-19

    Uptake of Mycobacterium avium subsp. paratuberculosis (MAP) by calves in the first days of life from colostrum, milk and faeces is regarded an important moment of transmission. The objective of this study was to quantify the association between the MAP status of dams as determined by the presence of MAP DNA and antibody in colostrum and that of DNA in faeces and the environment with subsequent MAP shedding of their daughters. A cohort of 117 dam-daughter pairs giving birth/being born on eight commercial dairy farms with endemic paratuberculosis was followed where colostrum, faecal and environmental samples (dust) were analysed for the presence of MAP using an IS900 real-time PCR. Antibodies in colostrum were measured by ELISA. Analysis of dust samples showed that on all farms environmental MAP exposure occurred continuously. In significantly more colostrum samples (48%) MAP DNA was detected compared to faecal samples (37%). MAP specific antibodies were present in 34% of the colostrum samples. In total MAP DNA was present in faecal samples of 41% of the daughters at least once during the sampling period. The association between faecal shedding in the offspring and the dam MAP status defined by MAP PCR on colostrum, MAP PCR on faeces or ELISA on colostrum was determined by an exact cox regression analysis for discrete data. The model indicated that the hazard for faecal shedding in daughters born to MAP positive dams was not significantly different compared to daughters born to MAP negative dams. When born to a dam with DNA positive faeces the HR was 1.05 (CI 0.6; 1.8) and with DNA positive colostrum the HR was 1.17 (CI 0.6; 2.3). When dam status was defined by a combination of both PCR outcomes (faeces and colostrum) and the ELISA outcome the HR was 1.26 (CI 0.9; 1.9). Therefore, this study indicates that neither the presence of MAP DNA in colostrum, MAP DNA in faeces nor the presence of MAP antibodies in colostrum of the dam significantly influences the hazard of

  17. Mapping areas at risk of diffuse phosphorus losses to water: a pilot study of Lake Haderslev Dam, Denmark.

    PubMed

    Andersen, Hans Estrup; Heckrath, Goswin; Thodsen, Hans

    2008-01-01

    Haderslev Dam is a 272 ha lake in southern Denmark with a high recreational value. For decades the lake has been severely eutrophicated due to excessive phosphorus loading. Major point sources were cut off in the early 1990s and an upstream wetland was recreated. However, the ecological quality remains unsatisfactory. In this study we estimate the importance of agriculture on diffuse phosphorus (P) input to the lake by modelling combined with independent estimates for contributions from scattered dwellings not connected to a sewer and from background losses. We apply a newly developed Danish P index to the lake catchment for mapping of risk areas for diffuse phosphorus losses. For risk areas we suggest mitigation measures and estimate the effect of the mitigation measures on the total P loading of the lake as well as the associated costs.

  18. Attributes of successful stock water ponds in southern Arizona

    Treesearch

    Barry L. Imler; Richard H. Wawkins; D. Phillip Guertin; Don W. Young

    2000-01-01

    The attributes of 20 ponds (or stock tanks) on the Nogales Ranger District of the Coronado National Forest were studied in detail by groups. Two contrasting groups, judged to be either functional (n = 11) or nonfunctional (n = 9) were used in the study. Differences between the groups were evaluated on the basis of attributes of the ponds themselves, the contributing...

  19. About the interest of a zooplankton compartment in pond systems: methodology to study the growth kinetic of Daphnia pulex on Scenedesmus sp.

    PubMed

    Liady, M N D; Tangou, T T; Fiogbe, E D; Cauchie, H-M; Vasel, J-L

    2015-01-01

    A reliable characterization of cladocerans' growth kinetic on their substrates is crucial for the estimation of their biochemical conversion rate in pond models. Although many studies reported cladocerans' growth inhibitions by high chlorophyceae contents, their growth kinetics had continued to be described in many pond system models by Monod-type kinetic, which describes growth saturation by high substrate contents, but fails to explain the disappearance of cladocerans observed during chlorophyceae's bloom periods. This study aimed to develop a methodology and assess whether growth-inhibition-type models used to describe microbial growth kinetics can be applicable to cladocerans. Experiments were carried out using Daphnia pulex populations and Scenedesmus sp. First, biomass of D. pulex was measured through digital image processing (DIP) during growth experiments. Then, three candidate models (i.e., Andrews, Edward and Haldane models), along with the Monod model, were fitted to the observed data and compared. The results showed that the DIP technique provided reliable results for estimating the biomass of D. pulex. Our findings show that the candidate growth inhibition-type models satisfactorily described D. pulex's growth kinetic (86% variance accounted for). Scenesdemus sp. were not strong inhibitors of the growth of D. pulex (high inhibition constant and low half-saturation constant found).

  20. A case study of enteric virus removal and insights into the associated risk of water reuse for two wastewater treatment pond systems in Bolivia.

    PubMed

    Symonds, E M; Verbyla, M E; Lukasik, J O; Kafle, R C; Breitbart, M; Mihelcic, J R

    2014-11-15

    Wastewater treatment ponds (WTP) are one of the most widespread treatment technologies in the world; however, the mechanisms and extent of enteric virus removal in these systems are poorly understood. Two WTP systems in Bolivia, with similar overall hydraulic retention times but different first stages of treatment, were analyzed for enteric virus removal. One system consisted of a facultative pond followed by two maturation ponds (three-pond system) and the other consisted of an upflow anaerobic sludge blanket (UASB) reactor followed by two maturation (polishing) ponds (UASB-pond system). Quantitative polymerase chain reaction with reverse transcription (RT-qPCR) was used to measure concentrations of norovirus, rotavirus, and pepper mild mottle virus, while cell culture methods were used to measure concentrations of culturable enteroviruses (EV). Limited virus removal was observed with RT-qPCR in either system; however, the three-pond system removed culturable EV with greater efficiency than the UASB-pond system. The majority of viruses were not associated with particles and only a small proportion was associated with particles larger than 180 μm; thus, it is unlikely that sedimentation is a major mechanism of virus removal. High concentrations of viruses were associated with particles between 0.45 and 180 μm in the UASB reactor effluent, but not in the facultative pond effluent. The association of viruses with this size class of particles may explain why only minimal virus removal was observed in the UASB-pond system. Quantitative microbial risk assessment of the treated effluent for reuse for restricted irrigation indicated that the three-pond system effluent requires an additional 1- to 2-log10 reduction of viruses to achieve the WHO health target of <10(-4) disability-adjusted life years (DALYs) lost per person per year; however, the UASB-pond system effluent may require an additional 2.5- to 4.5-log10 reduction of viruses.

  1. The application of remote sensing in the environmental risk monitoring of tailings pond: a case study in Zhangjiakou area of China

    NASA Astrophysics Data System (ADS)

    Xiao, Rulin; Shen, Wenming; Fu, Zhuo; Shi, Yuanli; Xiong, Wencheng; Cao, Fei

    2012-10-01

    As a kind of huge environmental risk source, tailings pond could cause a huge environmental disaster to the downstream area once an accident happened on it. Therefore it has become one key target of the environmental regulation in china. Especially, recently environmental emergencies caused by tailings pond are growing rapidly in China, the environmental emergency management of the tailings pond has been confronting with a severe situation. However, the regulatory agency is badly weak in the environmental regulation of tailings pond, due to the using of ground surveys and statistics which is costly, laborious and time consuming, and the lacking of strong technical and information support. Therefore, in this paper, according to the actual needs of the environmental emergency management of tailings pond, we firstly make a brief analysis of the characteristics of the tailings pond and the advantages and capability of remote sensing technology, and then proposed a comprehensive and systematic indexes system and the method of environmental risk monitoring of tailings pond based on remote sensing and GIS. The indexes system not only considers factors from the upstream area, the pond area and the downstream area in a perspective of the risk space theory, but also considers factors from risk source, risk receptor and risk control mechanism in a perspective of risk systems theory. Given that Zhangjiakou city has up to 580 tailings pond and is nearly located upstream of the water source of Beijing, so finally we apply the proposed indexes system and method in Zhangjiakou area in China to help collect environmental risk data of tailings pond in that area and find out it works well. Through the use case in Zhajiakou, the technique of using remote sensing to monitor environmental risk of tailings pond is feasible and effective, and would contribute to the establishment of `Space-Ground' monitoring network of tailings pond in future.

  2. Influence of Beaver Dams on Channel Complexity, Hydrology, and Temperature Regime in a Mountainous Stream

    NASA Astrophysics Data System (ADS)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2013-12-01

    Beaver dams and beaver activity affect hydrologic processes, sediment transport, channel complexity and water quality of streams. Beaver ponds, which form behind beaver dams, increase in-channel water storage affecting the timing and volume of flow and resulting in the attenuation and flattening of the hydrograph. Channel complexity also increases the potential for transient storage (both surface and subsurface) and influences stream temperature. Impacts of beaver dams and beaver activity on stream responses are difficult to quantify because responses are dynamic and spatially variable. Few studies have focused on the reach scale temporal influences on stream responses and further research is needed particularly in quantifying the influence of beaver dams and their role in shaping the stream habitat. This study explores the changing hydrology and temperature regime of Curtis Creek, a mountainous stream located in Northern Utah, in a 560 m long reach where groundwater exchanges and temperature differences were observed over a three-year period. We have collected continuous stream discharge, stream temperature data and performed tracer experiments. During the first year, we were able to capture the pre-beaver activity. In the second year, we captured the impacts of some beaver activity with only a few dams built in the reach, while the third year included the effects of an entire active beaver colony. By the end of the study period, a single thread channel had been transformed into a channel with side channels and backwaters at multiple locations therefore increasing channel complexity. The cumulative influence of beaver dams on reach scale discharge resulted in a slightly losing reach that developed into a gaining reach. At the smaller sub-reach scale, both losing to gaining and gaining to losing transformations were observed. Temperature differences showed a warming effect of beaver dams at the reach scale. The reach stream temperature difference increased on

  3. PERSPECTIVE ON LANDSLIDE DAMS.

    USGS Publications Warehouse

    Schuster, Robert L.; Costa, John E.; ,

    1986-01-01

    The most common types of mass movements that form landslide dams are rock and soil slumps and slides; mud, debris, and earth flows: and rock and debris avalanches. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snow melt, and earthquakes. Most landslide dams are remarkable short-lived. In a sample of 63 documented cases, 22 percent of the landslide dams failed in less than 1 day after formation, and half failed within 10 days. Overtopping was by far the most frequent cause of landslide-dam failure. Backwater flooding behind landslide dams can inundate communities and valuable agricultural land. Floods from the failure of landslide dams are smaller than floods from constructed dams impounding bodies of water with the same potential energy, but larger than floods from failure of ice dams. Secondary effects of landslide-dam failures include additional landslides as reservoir levels drop rapidly, aggradation of valleys upstream and downstream of the dams, and avulsive channel changes downstream.

  4. Elwha River Riparian Vegetation Response to Dams and Dam Removal

    NASA Astrophysics Data System (ADS)

    Shafroth, P. B.; Brown, R. L.; Clausen, A. J.; Chenoweth, J.

    2012-12-01

    Riparian vegetation is highly diverse and influences habitat of aquatic and terrestrial wildlife. Riparian vegetation dynamics are driven by stream flow regime, and fluxes of sediment and large woody debris, all of which can be altered by river damming. Dam removal is often implemented, in part, to help restore degraded riparian vegetation by reversing the alteration of these key drivers. However, increased disturbance and sediment flux associated with transport and exposure of trapped reservoir sediment can complicate a simple return to pre-dam conditions and can favor exotic species. We are studying the effects of dams and their removal on riparian vegetation along the Elwha River in Washington State, where removal of two large dams began in September 2011. To characterize vegetation composition, structure, and diversity prior to dam removal, we sampled 60-150 vegetation plots in 2004, 2005, and 2010 along five cross-valley transects in each of three river reaches: above both dams (upper reach), between the dams (middle reach), and downstream of both dams (lower reach). In summer 2012, we resampled a subset of our plots in the lower and middle reaches to evaluate vegetation and geomorphic change. We also sampled vegetation, topography, and grain size along newly-established transects within the exposed former reservoir behind Elwha Dam, which was removed in 2011 and 2012. Plant community distribution on bottomland geomorphic surfaces along the Elwha is typical of other systems in the region. We identified 8 overstory and 26 understory communities using multivariate analyses. Young bar surfaces (5-20 yrs) were dominated by willow, red alder, and black cottonwood. Floodplains and transitional fluvial terraces (<90yrs) were generally dominated by alder and cottonwood. Mature terraces (>90yrs) were often dominated by big-leaf maple. Douglas fir occurred on both young and old floodplains and terraces. Overstory species composition was more stable from 2005 to 2010

  5. Conceptual design of the Truscott brine lake solar-pond system, volume 1: Utility-independent scenario

    NASA Astrophysics Data System (ADS)

    1981-06-01

    A conceptual design was performed for a series of solar pond systems to provide pumping power for chloride control in the Red River Basin. In the chloride control project, briny waters are diverted so as not to pollute portable water. The diverted brine is stored in a dammed natural basin where, with the aid of natural evaporation, the brine is concentrated to the salinities required for the solar ponds. The brine is transferred to the ponds and injected at the proper levels to establish the gradients and storage layers. The solar ponds are to be located within the Truscott, Texas brine impoundment lake. Heat will be extracted from the ponds and used to drive organic Rankine-cycle turbine generators. The electricity produced will serve the pumping needs of the chloride control project, pump brine from the natural source to the evaporation ponds, pump concentrated brine from the evaporation ponds to the solar ponds, maintain the solar ponds, and supply all system parasitic loads. It was found that five solar ponds with eight organic Rankine-cycle turbine-generators would serve both the average and peaking power requirements of the pumping stations in the Truscott area as they come on-line.

  6. Experimental canopy removal enhances diversity of vernal pond amphibians.

    PubMed

    Skelly, David K; Bolden, Susan R; Freidenburg, L Kealoha

    2014-03-01

    Vernal ponds are often treated as protected environments receiving special regulation and management. Within the landscapes where they are found, forest vegetation frequently dominates surrounding uplands and can grow to overtop and shade pond basins. Two bodies of research offer differing views of the role of forest canopy for vernal pond systems. Studies of landscape conversion suggest that removing forest overstory within uplands can cause local extinctions of amphibians by altering terrestrial habitat or hindering movement. Studies of canopy above pond basins imply an opposite relationship; encroachment of overstory vegetation can be associated with local extinctions potentially via changes in light, thermal, and food resource environments. Unresolved uncertainties about the role of forest canopy reveal significant gaps in our understanding of wetland species distributions and dynamics. Any misunderstanding of canopy influences is simultaneously important to managers because current practices emphasize promoting or conserving vegetation growth particularly within buffers immediately adjacent to ponds. We evaluated this apparent contradiction by conducting a landscape-scale, long-term experiment using 14 natural vernal ponds. Tree felling at six manipulated ponds was limited in spatial scope but was nevertheless effective in increasing water temperature. Compared with eight control ponds, manipulated ponds maintained more amphibian species during five years post-manipulation. There was little evidence that any species was negatively influenced, and the reproductive effort of species for which we estimated egg inputs maintained pretreatment population densities in manipulated compared with control ponds. Overall, our experiment shows that a carefully circumscribed reduction of overhead forest canopy can enhance the capacity of vernal ponds to support wildlife diversity and suggests a scale dependence of canopy influences on amphibians. These findings have

  7. Personal computer accelerates dam analysis

    SciTech Connect

    Slopek, R.J. )

    1991-12-01

    Analyzing the stability of a dam can require several months of calculations - depending upon the number of dam cross sections and the variety of loadings that are studied. Monenco Consultants Limited, an engineering firm with its head office in Calgary, Alberta, has evaluated the safety of existing dams at more than 40 water resource developments in the last 20 years. Realizing the complexity of these evaluations, Monenco engineers were interested in developing techniques that would reduce the hours of professional time required for stability calculations, and therefore the cost to the dams owners. The firm eventually developed a microcomputer program for its engineers to use in the stability analysis of concrete gravity dams and two spread-sheets to use with the program for analyzing uplift and internal stresses. Using the computer programs cuts man-hours spent in analysis by about 75 percent and reduces the possibility of error in multiple calculations. Ultimately, the programs allow the engineer to spend more time in detailed analysis of a structure during a safety evaluation and less time performing tedious calculations.

  8. Study of Active Faults in the Three Gorges Dam region by Detecting and Relocating Aftershocks

    NASA Astrophysics Data System (ADS)

    Huang, R.; Zhu, L.; Xu, Y.

    2014-12-01

    Seismicity in the Three Gorges Dam (TGD) region and its adjacent areas increased dramatically as the water- level of the TGD reservoir rises since its completion in 2003. Accordingly, many efforts have been put forward to quantify the seismicity and geological hazards in the region. However, the precise detective of earthquakes, especially for the minor ones, remains difficulty because of sparse distribution of permanent seismic stations. From December 2013 to June 2014, we deployed 30 three-component broadband seismic stations in the TGD region. During the deployment, we recorded two earthquakes of magnitudes lager than 5.0, one occurred on December 16th 2013 in Badong and another on March 30th 2014 in Zigui. We firstly used a sliding-window cross-correlation (SCC) detection technique to supplement the events catalog from the China Earthquake Networks Center. Over 500 new events with ML lager than 0.5 were detected. We then relocated 502 events out of the total 987 events using the double-difference (DD) relocation algorithm. We also determined moment tensors of some large earthquakes using gCAP. The results clearly show two active faults along Yangtze River with dips of 50 degrees and 90 degrees to a maximum depth of 10 km, respectively. And they also reveal that water might have permeated to a depth of 6 km corresponds to the interface of sediments and metamorphic basement beneath Zigui Basin. We thus preliminarily judge that the quakes are triggered by local stress adjustment resulting of fluctuation of Three Gorges reservoir's loading.

  9. Effects of riparian buffers on hydrology of northern seasonal ponds

    Treesearch

    Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

    2011-01-01

    Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

  10. Revisiting salt marsh resilience to sea level rise: Are ponds responsible for permanent land loss?

    NASA Astrophysics Data System (ADS)

    Mariotti, G.

    2016-12-01

    Ponds are un-vegetated rounded depressions commonly present on marsh platforms. The role of ponds on the long-term morphological evolution of tidal marshes is unclear - at times ponds expand but eventually recover the marsh platform, at other times ponds never recover and lead to permanent marsh loss. Existing field observations indicate that episodic disturbances of the marsh vegetation cause the formation of small (1-10 m) isolated ponds, even if the vegetated platform keeps pace with Relative Sea Level Rise (RSLR), and that isolated ponds tend to deepen and enlarge until they eventually connect to the channel network. Here I implement a simple model to study the vertical and planform evolution of a single connected pond. A newly connected pond recovers if its bed lies above the limit for marsh plant growth, or if the inorganic deposition rate is larger than the RSLR rate. A pond that cannot accrete faster than RSLR will deepen and enlarge, eventually entering a runaway erosion by wave edge retreat. A large tidal range, a large sediment supply, and a low rate of RSLR favor pond recovery. The model suggests that inorganic sediment deposition alone controls pond recovery, even in marshes where organic matter dominates accretion of the vegetated platform. As such, halting permanent marsh loss by pond collapse requires to increase inorganic sediment deposition. Because pond collapse is possible even if the vegetated platform keeps pace with RSLR, I conclude that marsh resilience to RSLR is less than previously quantified.

  11. Revisiting salt marsh resilience to sea level rise: Are ponds responsible for permanent land loss?

    NASA Astrophysics Data System (ADS)

    Mariotti, G.

    2016-07-01

    Ponds are unvegetated rounded depressions commonly present on marsh platforms. The role of ponds on the long-term morphological evolution of tidal marshes is unclear—at times ponds expand but eventually recover the marsh platform, at other times ponds never recover and lead to permanent marsh loss. Existing field observations indicate that episodic disturbances of the marsh vegetation cause the formation of small (1-10 m) isolated ponds, even if the vegetated platform keeps pace with relative sea level rise (RSLR) and that isolated ponds tend to deepen and enlarge until they eventually connect to the channel network. Here I implement a simple model to study the vertical and planform evolution of a single connected pond. A newly connected pond recovers if its bed lies above the limit for marsh plant growth or if the inorganic deposition rate is larger than the RSLR rate. A pond that cannot accrete faster than RSLR will deepen and enlarge, eventually entering a runaway erosion by wave edge retreat. A large tidal range, a large sediment supply, and a low rate of RSLR favor pond recovery. The model suggests that inorganic sediment deposition alone controls pond recovery, even in marshes where organic matter dominates accretion of the vegetated platform. As such, halting permanent marsh loss by pond collapse requires to increase inorganic sediment deposition. Because pond collapse is possible even if the vegetated platform keeps pace with RSLR, I conclude that marsh resilience to RSLR is less than previously quantified.

  12. Effects of hydrology on zooplankton communities in high-mountain ponds, Mount Rainier National Park, USA

    USGS Publications Warehouse

    Girdner, Scott; Larson, Gary L.

    1995-01-01

    Ten high-mountain ponds in Mount Rainier National Park, Washington State, were studied from ice-out in June through September1992 to investigate the influences of fluctuating pond volumes on zooplankton communities. All of the ponds were at maximum volume immediately after ice-out. The temporary pond with the shortest wet phase was inhabited by rotifer taxa with short generation times and a crustacean taxon with the ability to encyst as drought-resistant resting bodies at immature stages of development. Dominant zooplankton taxa in three other temporary ponds and six permanent ponds were similar. Rotifer densities typically were lower in temporary ponds relative to those in permanent ponds, although Brachionus urceolaris was abundant shortly before the temporary ponds dried. Large volume loss was associated with large declines in total abundances of crustacean populations. Daphnia rosea was not present in temporary ponds following fall recharge. In deep-permanent ponds, copepods had slower developmental rates, smaller temporal changes in total abundances of crustacean populations and two additional large-bodied crustacean taxa were present relative to the characteristics of crustacean communities in shallow-permanent ponds. Owing to their small sizes and sensitivity to environmental change, collectively ponds such as these may provide an early signal of long-term climate change in aquatic systems.

  13. Key Impact Factors on Dam Break Fatalities

    NASA Astrophysics Data System (ADS)

    Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

    2016-12-01

    Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

  14. An estimate of the impact of trapped melt ponds on sea ice thinning

    NASA Astrophysics Data System (ADS)

    Flocco, Daniela; Feltham, Daniel; Schroeder, David

    2013-04-01

    Melt ponds form on Arctic sea ice during the melting season and their presence affects the heat and mass balance of the ice cover. Towards the end of the melt season melt ponds cover up to 50% of the sea ice area decreasing the value of the surface albedo by up to 20%. The dramatic impact of melt ponds on the albedo feedback mechanism for sea ice melt has been demonstrated in previous studies. Here, we focus on the refreezing of melt ponds. As the ponds freeze from above, they gradually release latent heat that inhibits basal ice growth. The refreezing process can take up to three months. Freezing of the melt pond comes to an halt if the pond's freezing point reaches the air temperature since the Stefan condition for sea ice growth is not met anymore. Since the ice in presence of melt pond will stay thinner and flatter for longer, the areas where ponds are present are likely location for pond formation in the subsequent years. The presence of a pond trapped in the ice delays significantly the sea ice growth at locations where melt ponds form. The potential volume loss of sea ice per year in the Arctic considering a melt pond cover of 20% is up to 1000 km3 without considering the presence of snow. Within the ASBO (Arctic Synoptic Basin-wide Observations) project we have developed a model of refreezing melt ponds that uses mushy layer theory to describe the sea ice and takes account of the presence of salt in the refreezing melt pond. We use this model to investigate the rate at which melt ponds refreeze, releasing latent heat, and their impact on sea ice growth. In this work we would like to present model result with climatology input. We will give an estimate of the impact of the melt pond presence on sea ice growth in the Arctic basin.

  15. A multidisciplinary study for mining landscape reclamation: A study case on two tailing ponds in the Region of Murcia (SE Spain)

    NASA Astrophysics Data System (ADS)

    Martínez-Pagán, P.; Faz, A.; Acosta, J. A.; Carmona, D. M.; Martínez-Martínez, S.

    The aim of this work was to evaluate the mobility of Pb, Cu, Zn and Cd in two tailing ponds (Brunita and San Cristobal) from mine activity in the Southeast of Spain before applying reclamation measures for reducing the risk for human and environment. To achieve this objective, five profiles of electrical resistivity imaging (ERI) in Brunita, three profiles in San Cristobal, a drill-hole in each pond and undisturbed columns amended with marble waste for leaching experiments were taken. Results showed that all layers of the two ponds exceed the maximum Pb and Zn concentrations allowed by the selected European legislations. In both ponds, the mixture of tailings with natural soil is the main process involved in soil pollution under the ponds. However, due to high pH in the substrate the metals are precipitated and their solubility reduced, therefore there is not a risk of leaching to groundwater. At Brunita tailing pond electrical resistivity sections displayed some lower electrical resistivity region into the bedrock which has been described as some fault occurrence due to breaking events suffered by the tailing pond. At San Cristobal tailing pond geochemical results were consistent with data obtained by the electrical resistivity imaging (ERI) method where no evidence of faults or cracks into the bedrock and the ponds were observed. Therefore, no preferential pathways of acid mine drainages containing heavy metals were reported. Leaching experiments indicated that, after 11 weeks of leaching, amended and control columns showed comparable values of pH (∼2.3) and similar trends for Cu, Cd and Zn, with a very drastic decrease up to week 3 and thereafter the tendency was to reach near steady-state conditions. In contrast, the evolution of Pb showed that marble amended reduces significantly its concentration over time compared with the control. In accordance with the results, future reclamation action should be based on the reduction of heavy metal mobility by means of

  16. Toward policies and decision-making for dam removal.

    PubMed

    Doyle, Martin W; Harbor, Jon M; Stanley, Emily H

    2003-04-01

    Dam removal has emerged as a critical issue in environmental management. Agencies responsible for dams face a drastic increase in the number of potential dam removals in the near future. Given limited resources, these agencies need to develop ways to decide which dams should be removed and in what order. The underlying science of dam removal is relatively undeveloped and most agencies faced with dam removal lack a coherent purpose for removing dams. These shortcomings can be overcome by the implementation of two policies by agencies faced with dam removal: (1) the development and adoption of a prioritization scheme for what constitutes an important dam removal, and (2) the establishment of minimum levels of analysis prior to decision-making about a dam removal. Federal and state agencies and the scientific community must encourage an initial experimental phase of dam removal during which only a few dams are removed, and these are studied intensively. This will allow for the development of the fundamental scientific understanding needed to support effective decision-making in the future and minimize the risk of disasters arising from poorly thought out dam removal decisions.

  17. 16. Parker Dam, only top fourth of dam visible, at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Parker Dam, only top fourth of dam visible, at 320' high, Parker Dam is one of the highest in the world. Much of this height is because dam penetrates well below river bottom to fasten to bedrock. - Parker Dam, Spanning Colorado River between AZ & CA, Parker, La Paz County, AZ

  18. Fragility Analysis of Concrete Gravity Dams

    NASA Astrophysics Data System (ADS)

    Tekie, Paulos B.; Ellingwood, Bruce R.

    2002-09-01

    Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

  19. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    NASA Astrophysics Data System (ADS)

    Li, Jianzhu; Sun, Huafeng; Feng, Ping

    2016-06-01

    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  20. Transport, dam passage, and size selection of adult Atlantic Salmon in the Penobscot River, Maine

    USGS Publications Warehouse

    Sigourney, Douglas B.; Zydlewski, Joseph; Hughes, Edward; Cox, Oliver

    2015-01-01

    Prior to 2012, returning adult Atlantic Salmon Salmo salar had to pass through fishways at three dams in the lower section of the Penobscot River, Maine: Veazie Dam (river kilometer [rkm] 48; removed in 2013), Great Works Dam (rkm 60; removed in 2012), and Milford Dam (rkm 62). To facilitate better passage through the lower river, a fish transport program was implemented in 2010 and 2011. Fish were captured at Veazie Dam and were either transported by truck above Milford Dam (TRKD group) or released into the head pond above Veazie Dam (run-of-the-river [ROR] group). To assess the efficacy of transport, we used PIT telemetry to compare the performance and passage of TRKD and ROR fish based on their (1) success in reaching one of the three dams upstream of Milford Dam, (2) time taken to reach an upstream dam (transit time), and (3) success in passing that upstream dam. In both years, the percentage of fish detected at upstream dams was higher for the TRKD group (82.4% in 2010; 78.6% in 2011) than for the ROR group (41.3% in 2010; 22.4% in 2011). In addition, median transit time was faster for TRKD fish (7 d in 2010; 5 d in 2011) than for ROR fish (23 d in 2010; 25 d in 2011). However, passage success through the upstream dams did not differ between the two release groups. Our analysis also revealed a strong, negative size-selective force on dam passage: larger fish were consistently less likely to successfully pass dams than smaller fish. Finally, environmental conditions also influenced passage success. Our analysis shows that the transport of adult Atlantic Salmon can be an effective means by which to increase migration success in systems where upstream passage is poor.

  1. Utilization of surface mine ponds in East Tennessee by breeding amphibians. Final report

    SciTech Connect

    Turner, L.J.; Fowler, D.K.

    1981-06-01

    Breeding amphibians were found in 21 of 24 ponds examined on the Ollis Creek Surface Mine in Campbell County, Tennessee. Twelve species of amphibians were identified in ponds that range from 4.0 to 8.0 in pH. Although ponds with low pH values were used by breeding amphibians, significantly more amphibian species were found in ponds with higher pH values. Findings indicated high biological productivity in the surface mine ponds examined. Aquatic vegetation was present in 20 of the 24 ponds. Aquatic insects and a diverse wildlife fauna utilized the study ponds. Surface mine ponds were found to supply an important habitat component for a variety of wildlife species.

  2. Salt-gradient Solar Ponds: Summary of US Department of Energy Sponsored Research

    NASA Technical Reports Server (NTRS)

    French, R. L.; Johnson, D. H.; Jones, G. F.; Zangrando, F.

    1984-01-01

    The solar pond research program conducted by the United States Department of Energy was discontinued after 1983. This document summarizes the results of the program, reviews the state of the art, and identifies the remaining outstanding issues. Solar ponds is a generic term but, in the context of this report, the term solar pond refers specifically to saltgradient solar pond. Several small research solar ponds have been built and successfully tested. Procedures for filling the pond, maintaining the gradient, adjusting the zone boundaries, and extracting heat were developed. Theories and models were developed and verified. The major remaining unknowns or issues involve the physical behavior of large ponds; i.e., wind mixing of the surface, lateral range or reach of horizontally injected fluids, ground thermal losses, and gradient zone boundary erosion caused by pumping fluid for heat extraction. These issues cannot be scaled and must be studied in a large outdoor solar pond.

  3. Microbiology of solar salt ponds

    NASA Technical Reports Server (NTRS)

    Javor, B.

    1985-01-01

    Solar salt ponds are shallow ponds of brines that range in salinity from that of normal seawater (3.4 percent) through NaCl saturation. Some salterns evaporate brines to the potash stage of concentration (bitterns). All the brines (except the bitterns, which are devoid of life) harbor high concentrations of microorganisms. The high concentrations of microorganisms and their adaptation to life in the salt pond are discussed.

  4. Dams and transnational advocacy: Political opportunities in transnational collective action

    NASA Astrophysics Data System (ADS)

    Fu, Teng

    Possible arguments to explain the gradual decline in big dam development and its site transferring from developed to developing countries include technical, economic, and political factors. This study focuses on the political argument---the rise of transnational anti-dam advocacy and its impact on state policy-making. Under what conditions does transnational anti-dam advocacy matter? Under what conditions does transnational advocacy change state dam policies (delay, scale down, or cancel)? It examines the role of transnational anti-dam actors in big dam building in a comparative context in Asia. Applying the social movement theory of political opportunity structure (POS) and using the qualitative case-study method, the study provides both within-case and cross-case analyses. Within-case analysis is utilized to explain the changing dynamics of big dam building in China (Three Gorges Dam and proposed Nu/Salween River dam projects), and to a lesser extent, Sardar Sarovar Project in India and Nam Theun 2 Dam in Laos. Different domestic and international POS (DPOS and IPOS) impact the strategies and outcomes of anti-dam advocacies in these countries. The degree of openness of the POS directly affects the capacity of transnational efforts in influencing state dam policies. The degree of openness or closure is measured by specific laws, institutions, discourse, or elite allies (or the absence of these) for the participation of non-state actors on big dam issues at a particular moment. This degree of openness is relative, varying over time, across countries and regions. This study finds that the impact of transnational anti-dam activism is most effective when both DPOS and IPOS are relatively open. Transnational anti-dam advocacy is least effective in influencing state dam policies when both DPOS and IPOS are relatively closed. Under a relatively open DPOS and closed IPOS, transnational anti-dam advocacy is more likely to successfully change state dam policies and even

  5. In-situ gamma-ray survey of rare-earth tailings dams--A case study in Baotou and Bayan Obo Districts, China.

    PubMed

    Li, Baochuan; Wang, Nanping; Wan, Jianhua; Xiong, Shengqing; Liu, Hongtao; Li, Shijun; Zhao, Rong

    2016-01-01

    An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of (238)U and (232)Th were 3.0 ± 1.0 mg/kg (range: 1.9-4.6 mg/kg) and 321 ± 31 mg/kg (range: 294-355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of (238)U and (232)Th were 5.7 ± 0.5 mg/kg (range: 5.3-6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5-276.3 mg/kg), respectively. The average (232)Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The (232)Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the (232)Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of (232)Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Production Responses of Channel Catfish to Minimum Daily Dissolved Oxygen Concentrations in Earthen Ponds

    USDA-ARS?s Scientific Manuscript database

    The purpose of this study was to determine the effects of the minimum daily dissolved oxygen (DO) concentration on production parameters of channel catfish Ictalurus punctatus in earthen ponds. Fifteen one-acre ponds (5 ponds per treatment) were managed as High Oxygen (minimum DO concentrations aver...

  7. Effects of acidification on algal assemblages in temporary ponds

    SciTech Connect

    Glackin, M.E.; Pratt, J.R.

    1994-12-31

    Atmospheric deposition monitoring in Pennsylvania has characterized a steep gradient of acidic ion depositions across the north-central portion of the state. This study evaluated acidification effects on the composition of algal assemblages in temporary ponds in two forested areas exposed to atmospheric deposition that varied in degree of acidity. Artificial substrates were used to sample and compare the algal assemblages in the two areas. Colonized communities were also transplanted to lower pH ponds to observe changes in species composition. A laboratory microcosm experiment manipulating pH was conducted to reduce the variables that differed between the two areas. Fewer algal taxa were present in lower pH ponds, on colonized substrates after transplant to lower pH ponds, and in lower pH laboratory treatments. Species composition was altered in the lower pH conditions. Most taxa that were excluded from the lower pH ponds naturally also did not survive when experimentally introduced to those conditions. These results suggest that acidification of temporary ponds can alter the structure of algal communities. There is interest in a possible link between acid deposition and reports of worldwide declines in amphibian populations. Algae are an important food source for larval amphibians, such as the wood frog, which require temporary ponds to breed. Changes in algal species composition could potentially impact the temporary pond and forest ecosystem.

  8. A model of the refreezing of melt ponds

    NASA Astrophysics Data System (ADS)

    Flocco, D.; Feltham, D. L.; Shroeder, D.

    2012-04-01

    Melt ponds form on Arctic sea ice during the melting season and their presence affects the heat and mass balance of the ice cover. Towards the end of the melt season melt ponds cover up to 50% of the sea ice area decreasing the value of the surface albedo by up to 20%. The dramatic impact of melt ponds on the albedo feedback mechanism for sea ice melt has been demonstrated in previous studies. Here, we focus on the refreezing of melt ponds. As the ponds freeze from above, they gradually release latent heat that inhibits basal ice growth. The refreezing process can take up to three months. Within the ASBO (Arctic Synoptic Basin-wide Observations) project we have developed a model of refreezing melt ponds that uses mushy layer theory to describe the sea ice and takes account of the presence of salt in the refreezing melt pond. We use this model to investigate the rate at which melt ponds refreeze, releasing latent heat, and their impact on sea ice growth. Model results are compared with in situ data collected by Ice Mass Balance buoys in the Arctic.

  9. Studies on the bacteriological qualities of the Buffalo River and three source water dams along its course in the Eastern Cape Province of South Africa.

    PubMed

    Chigor, Vincent N; Sibanda, Timothy; Okoh, Anthony I

    2013-06-01

    The Buffalo River and its dams are major surface water sources used for fresh produce irrigation, raw water abstraction and recreation in parts of the Eastern Cape Province in South Africa. Over a 12-month period (August 2010 to July 2011), we assessed the bacteriological qualities of water from the river and 3 source water dams along its course. Faecal indicator bacteria (FIB), including total coliform (TC), faecal coliform (FC) and enterococci (ENT) counts, were high and ranged as follows: 1.9 × 10(2)-3.8 × 10(7), 0-3.0 × 10(5) and 0-5.3 × 10(5) cfu/100 ml for TC, FC and ENT, respectively. Significantly (P<0.05) higher concentrations of FC and ENT were observed at the sampling sites located at the lower reaches of the river compared to the upper reaches, and at Bridle Drift Dam compared to the other two dams. FIB counts mostly exceeded the recommended maximum values suggested by national and international guidelines for safe fresh produce irrigation, domestic applications, full-contact recreation and livestock watering. These results show that the bacteriological qualities of the Buffalo River and dams were poor, and suggest that sewage was dumped into the Buffalo River during the study period. Urban runoffs and effluents of wastewater treatment plants appear to be important sources of faecal contamination in the river. We conclude that these water bodies represent significant public health hazards. Provision of adequate sanitary infrastructure will help prevent source water contamination, and public health education aimed at improving personal, household and community hygiene is imperative.

  10. 51. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- TAINTER GATE -- GENERAL ARRANGEMENT. M-L 26(R) 45/1 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  11. 9. Excavation work at Pleasant Dam (now called Waddell Dam). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Excavation work at Pleasant Dam (now called Waddell Dam). Photographer unknown, July, 22, 1926. Source: Maricopa County Municipal Water Conservation District Number One (MWD). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  12. Phytoremediation efficiency of Eichhornia crassipes in fly ash pond.

    PubMed

    Pandey, Vimal Chandra

    2016-01-01

    The present study was focused on field research to examine the phytoremediation potential of naturally grown Eichhornia crassipes in fly ash (FA) pond. Field results indicate the efficiency of E. crassipes for remediation of heavy metals from FA pond. The bioconcentration factor trend was Cr (3.75) > Cu (2.62) > Cd (1.05), and Cu (1.35) in root and stem, respectively. The survival and abundance growth of E. crassipes in the circumstance of heavy metal enriched FA pond is another highlight of the present research that reveals its toxitolerant characteristics. Thus, this lesson on phytoremediation proved that E. crassipes is a potential accumulator of Cu, Cr, and Cd from FA ponds and is a promising species for FA pond's remediation globally.

  13. Salton Sea Project, Phase 1. [solar pond power plant

    NASA Technical Reports Server (NTRS)

    Peelgren, M. L.

    1982-01-01

    A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe plant. The Solar Pond concept would be an environmental benefit to the Salton Sea by reversing the increasing salinity trend. The greatest cost drivers are the lake dike construction and pond sealing. Problems to be resolved include method of brine production from Salton Sea water for the first unit (which requires evaporation pond area and time), the high turbidity and color content of the Salton Sea water (which requires pretreatment), and other questions related to pond permeability, bio-activity and soil/brine chemical reactions. All technical and environmental problems appear solvable and/or manageable if care is taken in mitigating impacts.

  14. Gradient-zone erosion in seawater solar ponds

    SciTech Connect

    Shi, J.; Hart, R.A.; Kleis, S.J.; Bannerot, R.B.

    1997-02-01

    An experimental program has been conducted to examine the feasibility of using seawater solar ponds in mariculture operations along the Texas gulf coast to protect fish crops from the potentially lethal, cold temperatures experienced in outdoor ponds. Seawater solar ponds in the form of floating thermal refuge areas are proposed as a method for reducing the loss of heat from small sections of a pond. Gradient zone erosion under various ambient and operating conditions is examined. Comparisons with previous laboratory studies show a much lower entrainment rate in the natural environment. For conditions which are typical of those encountered in mariculture pond operation, the entrainment rate was found to depend only weakly on the Richardson number. For these conditions, a simple (linear) correlation of entrainment rate with wind speed was developed.

  15. Aquatic biodiversity in sedimentation ponds receiving road runoff - What are the key drivers?

    PubMed

    Sun, Zhenhua; Brittain, John E; Sokolova, Ekaterina; Thygesen, Helene; Saltveit, Svein Jakob; Rauch, Sebastien; Meland, Sondre

    2018-01-01

    Recently, increased attention has been paid to biodiversity conservation provided by blue-green solutions such as engineered ponds that are primarily established for water treatment and flood control. However, little research has been done to analyse the factors that affect biodiversity in such ponds. The purpose of this study was to evaluate the influence of environmental factors on aquatic biodiversity, mainly macroinvertebrate communities, in road sedimentation ponds in order to provide a foundation for recommendations on aquatic biodiversity conservation. Multivariate statistical methods, including unconstrained and constrained analysis, were applied to examine the relationships between organisms and the water quality as well as physical factors (including plant cover). Stepwise multiple regressions indicated that the most important variables governing the variation in the biological community composition were pond size, average annual daily traffic, metals, chloride, distance to the closest pond from study pond, dissolved oxygen, hydrocarbons, and phosphorus. The presence of most taxa was positively correlated with pond size and negatively correlated with metals. Small ponds with high pollutant loadings were associated with a low diversity and dominated by a few pollution tolerant taxa such as oligochaetes. A comprehensive understanding of impacts of various environmental factors on aquatic biodiversity is important to effectively promote and conserve aquatic biodiversity in such sedimentation ponds. Our results indicate that road sedimentation ponds should be designed large enough, because large ponds are likely to provide a more heterogeneous habitat and thus contain a species rich fauna. In addition, larger ponds seem to be less contaminated due to dilution compared to smaller ponds, thereby maintaining a higher biodiversity. Finally, creating some additional ponds in the vicinity of the sedimentation ponds in areas with few water bodies would increase the

  16. Pond dyes are Culex mosquito oviposition attractants

    PubMed Central

    2017-01-01

    significantly higher numbers of pupae, in the habitat where they had vegetation cover and shade. Discussion Our study has raised some interesting possibilities; one is that where used, pond dyes may be encouraging mosquitoes to breed in gardens in close proximity to people. Considering the concerns over potential future spread of disease in urban environments, this as well as shading of ponds and water butts, should inform future advice over reducing mosquito breeding and spread. PMID:28584705

  17. Impact of permafrost thaw on Arctic tundra pond geochemistry

    NASA Astrophysics Data System (ADS)

    Reyes, F.; Lougheed, V.

    2012-12-01

    Increasing evidence indicates the arctic tundra is changing physically, biologically, and chemically due to climate warming. With a warmer climate, permafrost is expected to thaw and influence the chemistry of arctic aquatic ecosystems. However, knowledge is limited on how geochemistry of arctic tundra pond ecosystems will respond. By re-sampling historical IBP ponds in Barrow, AK first sampled in the 1970s, previous studies have shown an increase in water temperature, nutrients and algal biomass through time. Results from this study indicate an increase of Ca, Mg, and Na in the water column, and a decrease in pH relative to the 1970s, suggesting an increased rate and magnitude of carbonate and Mg release. Seasonal trends were also examined to understand what processes, such as mineral weathering, peat decomposition and evaporation, were currently most influential in determining pond geochemistry. An increase in Ca/Na molar ratios, and carbonate and magnesium concentrations indicates that these tundra ponds are experiencing greater carbonate weathering compared to the 1970s and the rate of carbonate weathering increases in ponds as the summer progresses. However, increasing dissolved organic carbon (DOC) concentrations originating from peat decomposition are likely neutralizing additional inputs of carbonate, causing pond pH to decrease and exacerbating mineral weathering. A strong positive relationship between element concentrations and active layer pond thaw depth suggests that the origin of these additional solutes is likely from permafrost thaw. Active layer thaw depth has increased substantially over the past 40 years in the IBP ponds. Chloride/Bromide molar ratios and Deuterium/ 18-Oxygen isotope ratios will be used to determine the degree of evaporation occurring in tundra ponds. Ultimately, this study provides evidence for how geochemistry can identify the sources of chemical inputs to Arctic ponds affected by climate change and permafrost thaw.

  18. 78 FR 76288 - Notice of Intent To Prepare a Draft Environmental Impact Statement and Dam Safety Modification...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... and Dam Safety Modification Study Report for the Cherry Creek Project, Arapahoe County, Colorado... action to remediate dam safety concerns at Cherry Creek Dam. The dam safety concerns are primarily... that could be affected by such an event. Cherry Creek Dam and Lake is located on Cherry Creek, 11.4...

  19. METAPOPULATION STRUCTURE AND DYNAMICS OF POND BREEDING

    EPA Science Inventory

    Our review indicates that pond breeding amphibians exhibit highly variable spatial and temporal population dynamics, such that no single generalized model can realistically describe these animals. We propose that consideration of breeding pond permanence, and adaptations to pond ...

  20. Using seasonal forecasts in a drought forecasting system for water management: case-study of the Arzal dam in Brittany

    NASA Astrophysics Data System (ADS)

    Crochemore, Louise; Ramos, Maria-Helena; Perrin, Charles; Penasso, Aldo

    2014-05-01

    The Arzal dam is located at the outlet of the Vilaine River basin (10,000 km2) in Brittany, France. It controls a reservoir (50 hm3) managed for multiple water uses: drinking water, flood control, irrigation, sailing and fish by-passing. Its location in the estuary creates a physical divide between upstream freshwater and downstream saline water. The reservoir thus plays an essential role in the regional water management system. Its operational management during the summer season poses several challenges, mainly related to the quantification of future water inflows and the risks of having restricted water availability for its different uses. Indeed, the occurrence of severe drought periods between May and October may increase the risk of salt intrusion and drinking water contamination due to lock operations. Therefore it is important to provide decision-makers with reliable low-flow forecasts and risk-based visualization tools, which will support their choice of the best strategy for allocation of water among different users and stakeholders. This study focuses on an integrated hydro-meteorological forecasting system developed to forecast low flows upstream the Arzal dam and based on a lumped hydrological model. Medium-range meteorological forecasts from the ECMWF ensemble prediction system (51 scenarios up to 9 days ahead) are combined with seasonal meteorological forecasts also from ECMWF to provide extended streamflow forecasts for the summer period. The performance of the forecasts obtained by this method is compared with the performance of two benchmarks: (i) flow forecasts obtained using an ensemble of past observed precipitation series as precipitation scenarios, i.e. without any use of forecasts from meteorological models and (ii) flow forecasts obtained using the seasonal forecasts only, i.e. without medium-term information. First, the performance of ensemble forecasts is evaluated and compared by means of probabilistic scores. Then, a risk

  1. Walden Pond, Massachusetts: Environmental Setting and Current Investigations

    USGS Publications Warehouse

    Colman, John A.; Waldron, Marcus C.

    1998-01-01

    Introduction Walden Pond, in Concord, Massachusetts, is famous among lakes because of its unique social history. Walden was the setting for American naturalist Henry David Thoreau's well-known essay 'Walden; or, Life in the Woods,' first published in 1854. Thoreau lived and wrote at Walden Pond from July 1845 to September 1847. In 'Walden,' Thoreau combined highly admired writing on Transcendental philosophy with pioneering observations of aquatic ecology and physical aspects of limnology, the study of lakes. Because Thoreau also defended so effectively the value of living close to nature in the Walden woods, the pond is considered by many to be the birthplace of the American conservation movement. Visitors come from all over the world to the pond, which has been designated a National Historic Landmark, and its fame has resulted in a major fund drive to preserve the surrounding woods. Walden Pond has no surfacewater inflow or outflow, and much of its ground-water contributing area likely is preserved within the Walden Pond Reservation area (fig. 1). Only 15 miles from Boston, the pond is unusually clear and pristine for an urban-area lake. However, point sources of nutrients near the pond, and a large annual visitor attendance, concentrated during the summer when the swimming beach (fig. 2) is open, may contribute a nutrient load sufficient to change the pond environment. The occurrence of nuisance algal species, a recent beach closing, and an awareness of water-quality problems suffered by other ponds in the region raise concerns about the risk of ecological change at Walden Pond. Despite the role of Walden Pond as a cultural and environmental icon, little is known about the pond's ecological features, such as its internal nutrient cycling or the structure of its food web, nor have consistent measurements been made to determine whether these features are changing or are stable. Production rates of aquatic plants in lakes and ponds naturally undergo a slow increase

  2. Eutrophic urban ponds suffer from cyanobacterial blooms: Dutch examples.

    PubMed

    Waajen, Guido W A M; Faassen, Elisabeth J; Lürling, Miquel

    2014-01-01

    Ponds play an important role in urban areas. However, cyanobacterial blooms counteract the societal need for a good water quality and pose serious health risks for citizens and pets. To provide insight into the extent and possible causes of cyanobacterial problems in urban ponds, we conducted a survey on cyanobacterial blooms and studied three ponds in detail. Among 3,500 urban ponds in the urbanized Dutch province of North Brabant, 125 showed cyanobacterial blooms in the period 2009-2012. This covered 79% of all locations registered for cyanobacterial blooms, despite the fact that urban ponds comprise only 11% of the area of surface water in North Brabant. Dominant bloom-forming genera in urban ponds were Microcystis, Anabaena and Planktothrix. In the three ponds selected for further study, the microcystin concentration of the water peaked at 77 μg l(-1) and in scums at 64,000 μg l(-1), which is considered highly toxic. Microcystin-RR and microcystin-LR were the most prevalent variants in these waters and in scums. Cyanobacterial chlorophyll-a peaked in August with concentrations up to 962 μg l(-1) outside of scums. The ponds were highly eutrophic with mean total phosphorus concentrations between 0.16 and 0.44 mg l(-1), and the sediments were rich in potential releasable phosphorus. High fish stocks dominated by carp lead to bioturbation, which also favours blooms. As urban ponds in North Brabant, and likely in other regions, regularly suffer from cyanobacterial blooms and citizens may easily have contact with the water and may ingest cyanobacterial material during recreational activities, particularly swimming, control of health risk is of importance. Monitoring of cyanobacteria and cyanobacterial toxins in urban ponds is a first step to control health risks. Mitigation strategies should focus on external sources of eutrophication and consider the effect of sediment P release and bioturbation by fish.

  3. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    ERIC Educational Resources Information Center

    Barrett, Katharine; Willard, Carolyn

    This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

  4. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    ERIC Educational Resources Information Center

    Barrett, Katharine; Willard, Carolyn

    This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

  5. Plankton Management for Channel Catfish Nursery Ponds

    USDA-ARS?s Scientific Manuscript database

    We conducted a series of studies examining the fertilization practices used for channel catfish nursery ponds. The best fertilization protocol would be one that uses low-cost fertilizers, quickly establishes a desirable phytoplankton bloom, and produces the greatest number of large zooplankton. In...

  6. Microalgal separation from high-rate ponds

    SciTech Connect

    Nurdogan, Y.

    1988-01-01

    High rate ponding (HRP) processes are playing an increasing role in the treatment of organic wastewaters in sunbelt communities. Photosynthetic oxygenation by algae has proved to cost only one-seventh as much as mechanical aeration for activated sludge systems. During this study, an advanced HRP, which produces an effluent equivalent to tertiary treatment has been studied. It emphasizes not only waste oxidation but also algal separation and nutrient removal. This new system is herein called advanced tertiary high rate ponding (ATHRP). Phosphorus removal in HRP systems is normally low because algal uptake of phosphorus is about one percent of their 200-300 mg/L dry weights. Precipitation of calcium phosphates by autofluocculation also occurs in HRP at high pH levels, but it is generally not complete due to insufficient calcium concentration in the pond. In the case of Richmond where the studies were conducted, the sewage is very low in calcium. Therefore, enhancement of natural autoflocculation was studied by adding small amounts of lime to the pond. Through this simple procedure phosphorus and nitrogen removals were virtually complete justifying the terminology ATHRP.

  7. Performance of an intensive pond system treating municipal wastewater in a cold region.

    PubMed

    Wang, B; Qi, P; Wang, L; Lu, W; Liu, S; Zhao, F

    2005-01-01

    A full-scale intensive pond system (IPS) with shorter HRT was designed, constructed and operated in Jining, Inner-Mongolia for the treatment of municipal wastewater, which is a mixed domestic and industrial wastewater characterized by quite high SS and lower BOD5/COD ratio values or lower biodegradability. Therefore, the pond system was designed as an integrated intensive pond system (IIPS) consisting of settling/anaerobic pond (SAP), intensified anaerobic pond (IAP), facultative pond (FP), and polishing ponds (PPs). In order to improve the performance of the IPS, some intensified measures were made, including inlet and outlet even-distribution systems of each unit pond, package of biofilm carrier in IAP for the increase and even distribution of biomass; overflow waterfalls on the dikes between unit ponds for the increase of DO in pond water, gravel filtration dike (or dam) for removing suspended solids including algae, which have improved the performance of the IPS remarkably in terms of removal of main pollutants, such as SS, COD, BOD5, TN, NH3-N, TP and total bacteria. The final effluent from the IPS in warm seasons from May to October were SS 7.2-10.8 mg/L, BOD5 8.5-19.6 mg/L, COD 44.1 - 76.5 mg/L, and NH3-N 1.5-10.2 mg/L, which well meet Chinese national discharge standard (2nd class) of secondary municipal wastewater treatment plants, i.e. BOD5 and SS 30 mg/L respectively, COD 100 mg/L, and NH3-N 25 mg/L.

  8. A preliminary study of the algicidal mechanism of bioactive metabolites of Brevibacillus laterosporus on Oscillatoria in prawn ponds.

    PubMed

    Jia, Wen; Huang, Xianghu; Li, Changling

    2014-01-01

    The algae, Oscillatoria, is commonly found in prawn ponds and can lead to reduced productivity. We examined metabolites of the bacteria Brevibacillus laterosporus for algicidal qualities. To determine the possible algicidal mechanisms of these bioactive metabolites, different amounts of sterile filtrate of bacterial suspensions were added to cultures containing Oscillatoria. The dry weight, the concentrations of chlorophyll-a (chl-a), phycobiliprotein (PC, phycocyanin; APC, allophycocyanin; PE, phycoerythrin), and MDA (malondialdehyde) and the activities of SOD (superoxide dismutase), POD (peroxidase), and CAT (catalase) of algae were measured during the algicidal application. The results showed that lower concentrations of the sterile filtrate (addition ≤ 4 mL) accelerated the growth rate of Oscillatoria, but significant inhibition and lysis were observed with higher concentrations (addition ≥ 8 mL). In two trials (the additions were 8 mL and 10 mL, respectively), the algal dry weights were reduced by 26.02% and 45.30%, and the chl-a concentrations were decreased by 46.88% and 63.73%, respectively, after seven days. During the algicidal treatment, the concentrations of PC, APC, PE, and MDA and the activities of SOD, POD, and CAT were significantly increased in the early cultivation and declined quickly at later stages. Finally, the algae-lysing mechanism of the bioactive metabolites of the bacteria Brevibacillus laterosporus on Oscillatoria had been proposed.

  9. A Preliminary Study of the Algicidal Mechanism of Bioactive Metabolites of Brevibacillus laterosporus on Oscillatoria in Prawn Ponds

    PubMed Central

    Jia, Wen; Huang, Xianghu; Li, Changling

    2014-01-01

    The algae, Oscillatoria, is commonly found in prawn ponds and can lead to reduced productivity. We examined metabolites of the bacteria Brevibacillus laterosporus for algicidal qualities. To determine the possible algicidal mechanisms of these bioactive metabolites, different amounts of sterile filtrate of bacterial suspensions were added to cultures containing Oscillatoria. The dry weight, the concentrations of chlorophyll-a (chl-a), phycobiliprotein (PC, phycocyanin; APC, allophycocyanin; PE, phycoerythrin), and MDA (malondialdehyde) and the activities of SOD (superoxide dismutase), POD (peroxidase), and CAT (catalase) of algae were measured during the algicidal application. The results showed that lower concentrations of the sterile filtrate (addition ≤ 4 mL) accelerated the growth rate of Oscillatoria, but significant inhibition and lysis were observed with higher concentrations (addition ≥ 8 mL). In two trials (the additions were 8 mL and 10 mL, respectively), the algal dry weights were reduced by 26.02% and 45.30%, and the chl-a concentrations were decreased by 46.88% and 63.73%, respectively, after seven days. During the algicidal treatment, the concentrations of PC, APC, PE, and MDA and the activities of SOD, POD, and CAT were significantly increased in the early cultivation and declined quickly at later stages. Finally, the algae-lysing mechanism of the bioactive metabolites of the bacteria Brevibacillus laterosporus on Oscillatoria had been proposed. PMID:24744687

  10. Identification of Novel Genetic Loci for Intraocular Pressure: A Genomewide Scan of the Beaver Dam Eye Study

    PubMed Central

    Duggal, Priya; Klein, Alison P.; Lee, Kristine E.; Klein, Ronald; Klein, Barbara E. K.; Bailey-Wilson, Joan E.

    2008-01-01

    Clinical Relevance Glaucoma is a leading cause of blindness in the world, and the identification of genes that contribute to this disease is essential. Elevated intraocular pressure (IOP) is a principal risk factor for primary open-angle glaucoma (POAG), and an intriguing quantitative trait that may strongly influence the development of disease. Objectives The objective of this study was to identify genetic loci that control IOP. Methods We performed a genomewide scan of IOP, using 486 pedigrees ascertained through a population based cohort, the Beaver Dam Eye Study. Linkage analysis was performed using the modified Haseman-Elston regression models and variance components linkage analysis. Results Seven regions of interest were identified on chromosomes 2, 5, 6, 7, 12, 15 and 19. The novel linkage region on chromosome 19p had an empirical multipoint pvalue of 6.1×10−5. Two of the regions (2 and 19) are especially interesting since each has been identified as potential linkage regions for blood pressure. Conclusions The results of this genomewide scan provide evidence that a quantitative trait locus (QTL) may influence elevated IOP and may co-localize with blood pressure loci. These loci may control systemic pressure reflected in the eye and vascular system. PMID:17210855

  11. Utilization of surface mine ponds in East Tennessee by breeding amphibians

    SciTech Connect

    Turner, L.J.; Fowler, D.K.

    1981-06-01

    Of 24 ponds examined on Ollis Creek Surface Mine, Campbell County, Tennessee, 21 contained breeding amphibians. Twelve species of amphibians were identified in ponds that ranged from 4.0 to 8.0 in pH. Although ponds with low pH values were used by breeding amphibians, significantly more amphibian species were found in ponds with higher pH values. The average pH of ponds occupied by each amphibian species varied. Spring peepers (Hyla crucifer) occupied ponds with the lowest average pH (5.22) while upland chorus frogs (Pseudacris triseriata feriarum) utilized ponds with the highest average pH (6.33). Findings indicated high biological productivity in surface mine ponds. Aquatic vegetation was present in 20 of the 24 ponds. Aquatic insects and a diverse wildlife fauna utilized the study ponds. Large mammals (3 species), waterbirds (17 species), and snakes (2 species) were among those species observed. Surface mine ponds were found to supply an important habitat component for a variety of wildlife species and therefore improve the quality of wildlife habitat on the surface mines. In some areas, mine ponds are the only source of surface water available for wildlife use. 23 references, 9 figures, 5 tables.

  12. Experimental Research on the Dam-Break Mechanisms of the Jiadanwan Landslide Dam Triggered by the Wenchuan Earthquake in China

    PubMed Central

    Xu, Fu-gang; Yang, Xing-guo; Hao, Ming-hui

    2013-01-01

    Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation. PMID:23844387

  13. Experimental research on the dam-break mechanisms of the Jiadanwan landslide dam triggered by the Wenchuan earthquake in China.

    PubMed

    Xu, Fu-gang; Yang, Xing-guo; Zhou, Jia-wen; Hao, Ming-hui

    2013-01-01

    Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation.

  14. Factors Influencing Fecal Contamination in Pond of Bangladesh

    NASA Astrophysics Data System (ADS)

    Knappett, P. S.; Escamilla, V.; Layton, A.; McKay, L. D.; Emch, M.; Mailloux, B. J.; Williams, D. E.; Huq, M. R.; Alam, M.; Farhana, L.; Ferguson, A. S.; Sayler, G. S.; Ahmed, K.; Serre, M. L.; Akita, Y.; Yunus, M.; van Geen, A.

    2010-12-01

    Occurrence of diarrheal disease in villages in rural Bangladesh remains relatively common, even though many households have switched to tubewell water for drinking and cooking. One factor contributing to this may be exposure to fecal contamination in ponds, which are often used for bathing and fishing. The objective of this study is to determine the dominant sources of fecal pollution in typical ponds and to explore the relationship between local population, latrine density, latrine quality and concentrations of fecal bacteria and pathogens in pond water. Forty-three ponds were sampled and analyzed for E. coli using culture-based methods and for E. coli, Bacteroides and adenovirus using quantitative PCR. Population and sanitation infrastructure were surveyed and compared to levels of pond fecal contamination. Molecular fecal source tracking using Bacteroides, determined that humans were the dominant source of fecal contamination in 79% of the ponds. Ponds directly receiving latrine effluent had the highest concentrations of fecal indicator bacteria. Concentrations of fecal indicator bacteria correlated with population surveyed within a distance of 30-70 m (p<0.01) and total latrines surveyed within 50-70 m (p<0.05). Unsanitary latrines with visible effluent within the pond drainage basin were also significantly correlated to fecal indicator concentrations (p<0.05). The vast majority of the surveyed ponds contained unsafe levels of fecal contamination primarily due to unsanitary latrines, and to lesser extent to sanitary latrines and cattle. Since the majority of fecal pollution is from humans, use of pond water could help explain the persistence of diarrheal disease in rural Bangladesh.

  15. Focusing attention on dam safety

    SciTech Connect

    Barnes, M.J.

    1992-09-01

    When people think of hydropower, an image of a dam often comes to mind. Indeed, at most high-hazard dams, there is a hydro plant. A North American hydro industry survey shows that dams and their safety are a priority among project owners. The survey identified several recent dam safety activities: development of safety evaluation programs; dam rehabilitation for greater stability; dam monitoring installations; seismic strengthening; and emergency preparedness.

  16. Schoolyard Ponds: Safety and Liability.

    ERIC Educational Resources Information Center

    Danks, Sharon Gamson

    2001-01-01

    Engaging, attractive schoolyard ponds provide habitat for wildlife and hold great educational promise. Reviews water safety and liability issues including mud, stagnant pond water that serves as mosquito breeding grounds, and drowning. Offers ideas for creatively addressing those issues through site planning, shallow water depth, signage and…

  17. Schoolyard Ponds: Safety and Liability.

    ERIC Educational Resources Information Center

    Danks, Sharon Gamson

    2001-01-01

    Engaging, attractive schoolyard ponds provide habitat for wildlife and hold great educational promise. Reviews water safety and liability issues including mud, stagnant pond water that serves as mosquito breeding grounds, and drowning. Offers ideas for creatively addressing those issues through site planning, shallow water depth, signage and…

  18. Natural Dams as Tipping Points in Himalayan Erosion (Invited)

    NASA Astrophysics Data System (ADS)

    Korup, O.

    2010-12-01

    Natural dams result from hillslope, glacial, volcanic, and other sediment inputs that temporarily overwhelm the transport capacity along a given river reach. Such blockages are tipping points in which fluvial erosion and sediment transport rapidly switch to aggradation and vice versa even in the most powerful of rivers, thus eventually modulating both rates and duration of river incision into bedrock. Conspicuous clusters of hundreds of large natural dams occur in several major watersheds draining the Himalayan syntaxes and the southern Himalayan front, including the Indus, Yarlung Tsangpo, Sutlej, Kali Gandaki, and Arun. The Indus features the largest concentration of giant landslide dams known worldwide, whereas the Yarlung Tsangpo seems largely devoid of comparable landslide dams. Glacial dams such as river-blocking moraines are limited to headwaters where topography intersects the regional snowline. By forming dams and protective alluvial fill, glaciers and landslides help retard headward fluvial bedrock incision into parts of the Tibetan Plateau interior, limiting its dissection in addition to effects of upstream aridity and localized rock uplift. A growing number of radiometric age constraints on widely exposed lake sediments and backwater terraces support the notion that large tracts of these rivers had been repeatedly ponded for as long as several tens of thousands of years during the Late Quaternary. High local topographic relief in buffers along these rivers characterizes conspicuous knickzones, and helps pinpoint first-order differences in the type and potential longevity of these natural dams. Patterns of low-temperature thermochronometric data corroborate that peaks in mean local relief, spatially coinciding with peaks in long-term exhumation rates, act as a regionally consistent downstream limit to the preservation potential of natural dams. If indeed glacier and landslide dams act as a negative feedback in response to fluvial dissection of parts of

  19. National Dam Safety Program. Larchwood Lake Dam (Inventory Number NY 727), Susquehanna River Basin, Otsego County, New York. Phase I Inspection Report,

    DTIC Science & Technology

    1981-08-04

    analysis on tle- ph7sica. condition of the dam as of the report date. Information and analysis are based on Visual inspection of the dam by the...identify expeditiously those dams which may pose hazards to human life or property. The assessment of the general condition of the dam is based upon...studies. In reviewing this report, it should be realized that the reported condition of the dam is based on observations of field conditions at the time

  20. Comparison of physico-chemical parameters and zooplankton diversity in two perennial ponds at Aligarh, India.

    PubMed

    Parveen, Saltanat; Abdel Mola, Hesham R

    2013-07-01

    Investigations were carried out on the diversity of zooplankton in relation to physico-chemical parameters of two perennial ponds (Chautal Pond and Medical Pond) of Aligarh, India. Thirty nine species of holoplankton were identified belonging to copepoda (2 species), rotifera (28 species), cladocera (6 species) and protozoa (3 species). Other forms; like as meroplankton (insects) and tychoplankton (nematodes and ostracodes) were also recorded. Higher values of physico-chemical parameters and low zooplankton diversity were recorded in the Chautal Pond, whereas low values of physico-chemical parameters and high diversity were recorded in the Medical Pond. Ostracods considered to be the most dominant group in Medical Pond (32.16% of the total zooplankton) while Cladocerans are considered to be the most dominant group in Chautal Pond (38.83% of the total zooplankton). Rotifera contributed more in Medical Pond (16.42%) as compared to Chautal Pond (15.81%). Five species of Brachionus was recorded during study. Out of five, four Brachionus species were recorded in Chautal Pond while only two species were recorded in Medical pond. This indicates that Chautal Pond is more eutrophic than Medical pond. In addition, higher carbon dioxide values (37-105 mg l(-1)), low dissolved oxygen (0.7-3.3 mg I(-1)) and higher electrical conductivity values (1069-1691 mg l(-1)) were also indicative of eutrophic nature of Chautal Pond. Present study also revealed that total zooplankton species, species richness and diversity indices (Evenness, Shannon-Winner and Simpson) were comparatively higher in Medical pond. The rotifer species Philodina roseola (146 Org. l(-1)) and Monstyla closterocerca (109 Org. l(-1)) was dominated in Medical Pond while the rotifers Brachionus urceolaris (512 Org. l(-1)) and the cladocern species Ceriodaphnia cornuta (1540 Org. l(-1)) dominated in Chautal Pond during post-monsoon season. This might be due to the effect of rain water which played an important role in

  1. Socioeconomic and Institutional Dimensions of Dam Removals: The Wisconsin Experience

    PubMed

    Born; Genskow; Filbert; Hernandez-Mora; Keefer; White

    1998-05-01

    / There are tens of thousands of small dams in the United States; many of these aging structures are deteriorating. Governments and dam owners face decisions regarding repair or removal of these structures. Along with the many benefits society derives from dams and their impoundments, numerous recent ecological studies are revealing the extensive alteration and degradation of river ecosystems by dams. Dam removal-a principal restoration strategy-is an infrequent event. The major reasons for removal have been public safety and the high costs associated with repair; the goal of river ecosystem restoration now warrants greater attention. Substantial study is being given to the environmental aspects of dams and dam removals, but very little attention has been given to the socioeconomic and institutional dimensions associated with the removal of dams, although these factors play a significant role in the removal decision-making process. Based on a case study of dam removals in Wisconsin-where more than 30 of the state's 3600 small dams have been removed in the past few decades-legal, financial, and socioeconomic issues associated with dam removal are documented and assessed. Dam removal has been complex and contentious, with limited community-based support for removal and loss of the impounded waters. In cases examined here, the estimated costs of repairing a dam averaged more than three times the cost of removal. The availability of governmental financing has been a key determinant in removal decisions. Watershed-scale ecological considerations are not major factors for most local interests. As watershed management and restoration increasingly include dam removal options as part of an integrated strategy, more attention will need to be focused on socioeconomic factors and stakeholder perspectives-variables that strongly influence the viability of this management alternative.KEY WORDS: Dam removal; River restoration; Institutions; Stakeholders

  2. Detecting dam failures

    SciTech Connect

    Knarr, C.M.; Barker, T.J.; McKenery, S.F. )

    1994-06-01

    This article describes efforts by Southern California Edison to meet Federal Energy Regulatory Commission requirements for unattended dam monitoring against failure. The topics include a description of the two dam systems, monitoring system design and operation including warning sirens for remote camping areas, and installation of the systems.

  3. Dammed or Damned?

    ERIC Educational Resources Information Center

    Hirsch, Philip

    1988-01-01

    Summarizes issues raised at a workshop on "People and Dams" organized by the Society for Participatory Research in Asia. Objectives were to (1) understand problems created by dams for people, (2) consider forces affecting displaced populations and rehabilitation efforts, and (3) gain a perspective on popular education efforts among…

  4. Modeling an ancient Iranian dam system

    NASA Astrophysics Data System (ADS)

    Ertsen, Maurits; De Schacht, Tijs

    2013-04-01

    In Iran, along the northern and eastern fringes of the Pasargadae plain, five dam remains from the Achaemenid period (550-330 BCE) present an important footprint of the human impact and reshaping of the region. The dams are predominantly found in dry wadi beds. In the framework of the Joint Iranian-French Archaeological Project at Pasargadae, these dam sites were studied and excavated. Located 22 km to the north of Pasargadae in a small wadi, the Sad-i Didegan dam has a watershed of circa 46 square km, small compared with catchments of other known Achaemenid dams. It is an earth built gravity dam of circa 90 m wide, 21 m high and with a crown length of about 150 m. In the lower body of the dam, remains of a feeder canal and an accessible control infrastructure at the downstream flank of the dam were found. To the northwest, the dam site of Sad-i Shahidabad can be found, another large Achaemenid dam, which stored water from the perennial river of the Rud-i Polvar. This dam also had a similar canal and control structure. Close to the Sad-i Didegan area is a large earthwork, found to cross the watershed divide between Didegan and Shahidabad, consisting of a wide V-shaped trench of remarkable size: up to 100 m wide, a total length of at least 900 m and a maximum present day depth of 7.5 m. Even though the construction of the system in this case clearly was left unfinished, the remains echo the major investment of available labor. Given the contemporaneity of both dam sites, it is clear evidence of the more regionally and elaborately planned character of the hydrological endeavors in the Pasargadae area. Only through further study and future fieldwork (also obtaining absolute dating material), this impressive feature will be fully understood. This contribution proposes a possible use of the two dam system using a modern control simulation model. This analysis will also shed light on the question why the system probably never functioned.

  5. Flax pond ecosystem study: exchanges of CO/sub 2/ between a salt marsh and the atmosphere

    SciTech Connect

    Houghton, R.A.; Woodwell, G.M.

    1980-12-01

    Profiles of CO/sub 2/ concentration, windspeed, and temperature were used in the aerodynamic flux technique to calculate the CO/sub 2/ exchange between a Long Island salt marsh and the atmosphere. Uptake of CO/sub 2/ by the marsh during hours of sunlight and release during the night occurred during all times of the year. The rates of CO/sub 2/ exchange were highest during midsummer, 2.3 g CO/sub 2/.m/sup -2/.h/sup -1/ averaged over the daylight hours of July, and 1.3 g CO/sub 2/.m/sup -2/.h/sup -1/ for both uptake and release. The net 24-h exchange rates followed Spartina growth and senescence during the summer and fall, and photosynthesis of benthic algae during late winter and spring. There was a net uptake of Co/sub 2/ over 24 h by the marsh during all seasons except autumn. The net annual flow of carbon was from the atmosphere to Flax Pond (approx. = 300 g C.m/sup -2/.yr/sup -1/ averaged over the entire marsh ecosystem). This flux was larger than the net exchange of carbon between the marsh and either uplands, sediments, or coastal waters. The net uptake of CO/sub 2/ during summer was less than the net productivity of the vascular plants, indicating that some of the CO/sub 2/ assimilated by the plants came from heterotrophic respiration within the marsh. Nevertheless, respiration by the plants was by far the largest source of CO/sub 2/ from the marsh surface. Nighttime respiration of the ecosystem released a total of approx. = 510 g C.m/sup -2/.yr/sup -1/ to the atmosphere.

  6. Pond fractals in a tidal flat.

    PubMed

    Cael, B B; Lambert, Bennett; Bisson, Kelsey

    2015-11-01

    Studies over the past decade have reported power-law distributions for the areas of terrestrial lakes and Arctic melt ponds, as well as fractal relationships between their areas and coastlines. Here we report similar fractal structure of ponds in a tidal flat, thereby extending the spatial and temporal scales on which such phenomena have been observed in geophysical systems. Images taken during low tide of a tidal flat in Damariscotta, Maine, reveal a well-resolved power-law distribution of pond sizes over three orders of magnitude with a consistent fractal area-perimeter relationship. The data are consistent with the predictions of percolation theory for unscreened perimeters and scale-free cluster size distributions and are robust to alterations of the image processing procedure. The small spatial and temporal scales of these data suggest this easily observable system may serve as a useful model for investigating the evolution of pond geometries, while emphasizing the generality of fractal behavior in geophysical surfaces.

  7. Interconnected ponds operation for flood hazard distribution

    NASA Astrophysics Data System (ADS)

    Putra, S. S.; Ridwan, B. W.

    2016-05-01

    The climatic anomaly, which comes with extreme rainfall, will increase the flood hazard in an area within a short period of time. The river capacity in discharging the flood is not continuous along the river stretch and sensitive to the flood peak. This paper contains the alternatives on how to locate the flood retention pond that are physically feasible to reduce the flood peak. The flood ponds were designed based on flood curve number criteria (TR-55, USDA) with the aim of rapid flood peak capturing and gradual flood retuning back to the river. As a case study, the hydrologic condition of upper Ciliwung river basin with several presumed flood pond locations was conceptually designed. A fundamental tank model that reproducing the operation of interconnected ponds was elaborated to achieve the designed flood discharge that will flows to the downstream area. The flood hazard distribution status, as the model performance criteria, will be computed within Ciliwung river reach in Manggarai Sluice Gate spot. The predicted hazard reduction with the operation of the interconnected retention area result had been bench marked with the normal flow condition.

  8. Pond fractals in a tidal flat

    NASA Astrophysics Data System (ADS)

    Cael, B. B.; Lambert, Bennett; Bisson, Kelsey

    2015-11-01

    Studies over the past decade have reported power-law distributions for the areas of terrestrial lakes and Arctic melt ponds, as well as fractal relationships between their areas and coastlines. Here we report similar fractal structure of ponds in a tidal flat, thereby extending the spatial and temporal scales on which such phenomena have been observed in geophysical systems. Images taken during low tide of a tidal flat in Damariscotta, Maine, reveal a well-resolved power-law distribution of pond sizes over three orders of magnitude with a consistent fractal area-perimeter relationship. The data are consistent with the predictions of percolation theory for unscreened perimeters and scale-free cluster size distributions and are robust to alterations of the image processing procedure. The small spatial and temporal scales of these data suggest this easily observable system may serve as a useful model for investigating the evolution of pond geometries, while emphasizing the generality of fractal behavior in geophysical surfaces.

  9. Changes in tundra pond limnology: re-sampling Alaskan ponds after 40 years.

    PubMed

    Lougheed, Vanessa L; Butler, Malcolm G; McEwen, Daniel C; Hobbie, John E

    2011-09-01

    The arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK, were studied extensively in the 1970s; however, very little aquatic research has been conducted there for over three decades. Due to the rapid climate changes already occurring in northern Alaska, identifying any changes in the ponds' structure and function over the past 30-40 years can help identify any potential climate-related impacts. Current research on the IBP ponds has revealed significant changes in the physical, chemical, and biological characteristics of these ponds over time. These changes include increased water temperatures, increased water column nutrient concentrations, the presence of at least one new chironomid species, and increased macrophyte cover. However, we have also observed significant annual variation in many measured variables and caution that this variation must be taken into account when attempting to make statements about longer-term change. The Barrow IBP tundra ponds represent one of the very few locations in the Arctic where long-term data are available on freshwater ecosystem structure and function. Continued monitoring and protection of these invaluable sites is required to help understand the implications of climate change on freshwater ecosystems in the Arctic.

  10. Reported tailings dam failures. A review of the European incidents in the worldwide context.

    PubMed

    Rico, M; Benito, G; Salgueiro, A R; Díez-Herrero, A; Pereira, H G

    2008-04-01

    A detailed search and re-evaluation of the known historical cases of tailings dam failure was carried out. A corpus of 147 cases of worldwide tailings dam disasters, from which 26 located in Europe, was compiled in a database. This contains six sections, including dam location, its physical and constructive characteristics, actual and putative failure cause, sludge hydrodynamics, socio-economical consequences and environmental impacts. Europe ranks in second place in reported accidents (18%), more than one third of them in dams 10-20 m high. In Europe, the most common cause of failure is related to unusual rain, whereas there is a lack of occurrences associated with seismic liquefaction, which is the second cause of tailings dam breakage elsewhere in the world. Moreover, over 90% of incidents occurred in active mines, and only 10% refer to abandoned ponds. The results reached by this preliminary analysis show an urgent need for EU regulations regarding technical standards of tailings disposal.

  11. CO2 Efflux from Shrimp Ponds in Indonesia

    PubMed Central

    Sidik, Frida; Lovelock, Catherine E.

    2013-01-01

    The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored ‘blue’ carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO2) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO2 efflux from the floors and walls of shrimp ponds. Rates of CO2 efflux within shrimp ponds were 4.37 kg CO2 m−2 y−1 from the walls and 1.60 kg CO2 m−2 y−1 from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO2 emissions to the atmosphere between 5.76 and 13.95 Tg y−1. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO2 emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO2 released to atmosphere. PMID:23755306

  12. Performance of a baffled facultative pond treating piggery wastes.

    PubMed

    Zanotelli, C T; Medri, W; Belli, Filho P; Perdomo, C C; Mulinari, M R; Costa, R H R

    2002-01-01

    This paper shows the performance of a baffled facultative pond for the treatment of piggery wastes. The full-scale system is composed of an equalizer, one decanter (DP), two anaerobic ponds (LA1 and LA2), one facultative pond (LF), with five baffles, and one maturation pond with water hyacinths (LAG). The studies were conducted over a 12 month period in the west region of Santa Catarina, Brazil. The system was supplied daily with a volume of 3 m3/day of farm wastes. A good performance of the treatment system was obtained with average removal efficiencies of 98% for chemical oxygen demand, 93% for total solids, 98% for total phosphorus, 92% for total nitrogen, 7 log units of faecal coliforms and 5 log units of total coliforms. The facultative pond performed well, removing 43% of the chemical oxygen demand, 47% of total nitrogen and 54% of total phosphorus. It was found that the first baffle in the facultative pond was mainly responsible for the efficiency of this pond, and compared with another study the introduction of the baffles improved the removal efficiency by 20% for total phosphorus.

  13. The remains of the dam: what have we learned from 15 years of US dam removals?

    Treesearch

    Gordon E. Grant; Sarah L. Lewis

    2015-01-01

    Important goals for studying dam removal are to learn how rivers respond to large and rapid introductions of sediment, and to develop predictive models to guide future dam removals. Achieving these goals requires organizing case histories systematically so that underlying physical mechanisms determining rates and styles of sediment erosion, transport, and deposition...

  14. Wartime scars or reservoirs of biodiversity? The value of bomb crater ponds in aquatic conservation

    PubMed Central

    Vad, Csaba F.; Péntek, Attila L.; Cozma, Nastasia J.; Földi, Angéla; Tóth, Adrienn; Tóth, Bence; Böde, NóraA.; Móra, Arnold; Ptacnik, Robert; Ács, Éva; Zsuga, Katalin; Horváth, Zsófia

    2017-01-01

    Considering the ongoing loss of aquatic habitats, anthropogenic ponds are gaining importance as substitute habitats. It is therefore important to assess their functioning in comparison to their natural precursors. Here we assess the biodiversity value of sodic bomb crater ponds by comparing their gamma diversity to that of natural reference habitats, astatic soda pans, and assess their importance on the landscape level by studying alpha and beta diversity. We studied aquatic organisms ranging from algae to vertebrates in a dense cluster of 54 sodic bomb crater ponds in Central Europe. Despite the overall small area of the pond cluster, gamma diversity was comparable to that found in surveys of natural habitats that encompassed much wider spatial and temporal scales. We also found a considerable number of species shared with reference habitats, indicating that these anthropogenic habitats function as important refuge sites for several species that are associated with the endangered soda pans. Moreover, we found a number of regionally or worldwide rare species. Among the components of beta diversity, species replacement dominated community assembly. Individual ponds contributed similarly to beta diversity in terms of replacement, being equally important for maintaining high gamma diversity and emphasising the role of the pond network rather than individual ponds. This pattern was seen in all studied groups. Bomb crater ponds therefore acted as important contributors to aquatic biodiversity. Considering the tremendous losses of ponds throughout Europe, anthropogenic ponds should be taken into consideration in nature conservation, especially when occurring in pond networks. PMID:28529346

  15. Wartime scars or reservoirs of biodiversity? The value of bomb crater ponds in aquatic conservation.

    PubMed

    Vad, Csaba F; Péntek, Attila L; Cozma, Nastasia J; Földi, Angéla; Tóth, Adrienn; Tóth, Bence; Böde, NóraA; Móra, Arnold; Ptacnik, Robert; Ács, Éva; Zsuga, Katalin; Horváth, Zsófia

    2017-05-01

    Considering the ongoing loss of aquatic habitats, anthropogenic ponds are gaining importance as substitute habitats. It is therefore important to assess their functioning in comparison to their natural precursors. Here we assess the biodiversity value of sodic bomb crater ponds by comparing their gamma diversity to that of natural reference habitats, astatic soda pans, and assess their importance on the landscape level by studying alpha and beta diversity. We studied aquatic organisms ranging from algae to vertebrates in a dense cluster of 54 sodic bomb crater ponds in Central Europe. Despite the overall small area of the pond cluster, gamma diversity was comparable to that found in surveys of natural habitats that encompassed much wider spatial and temporal scales. We also found a considerable number of species shared with reference habitats, indicating that these anthropogenic habitats function as important refuge sites for several species that are associated with the endangered soda pans. Moreover, we found a number of regionally or worldwide rare species. Among the components of beta diversity, species replacement dominated community assembly. Individual ponds contributed similarly to beta diversity in terms of replacement, being equally important for maintaining high gamma diversity and emphasising the role of the pond network rather than individual ponds. This pattern was seen in all studied groups. Bomb crater ponds therefore acted as important contributors to aquatic biodiversity. Considering the tremendous losses of ponds throughout Europe, anthropogenic ponds should be taken into consideration in nature conservation, especially when occurring in pond networks.

  16. National Program for Inspection of Non-Federal Dams. Greenwater Pond Dam (MA 00204), Housatonic River Basin, Becket, Massachusetts. Greenwater Pond Dam (MA 00204) Phase I Inspection Report.

    DTIC Science & Technology

    1981-03-01

    bridae planking, wheel guards and railings on the bridge. The 4" x 4" trash rack walkway support posts were also replaced. Ilaintenance and repairs have...at bridae seats at spillway walls. a. Super Structure Bearings None Anchor Bolts Yes, but not used. L Bridge Seat Accumulated d4rt and debris

  17. 1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A GRAVITY SECTION IS THE THIRD DAM BUILT BY SEATTLE CITY LIGHT TO PROVIDE WATER FOR GORGE POWERHOUSE AND WAS COMPLETED IN 1961, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  18. Landslide-dammed lakes detection via ALOS/PALSAR InSAR DEM: A case study of the Iwate-Miyagi Nairiku earthquake

    NASA Astrophysics Data System (ADS)

    Asaka, Tomohito; Yamamoto, Yoshiyuki; Iwashita, Keishi; Kudou, Katsuteru; Fujii, Hisao; Nishikawa, Hajime; Sensing Specialist Yukihiro Suzuoki, Remote

    On 14th June 2008, the Japan Meteorological Agency recorded a 7.2 magnitude (Richter scale) earthquake with an epicenter depth of 8 km in the southern Iwate prefecture of the Tohoku region of Japan. In the hardest hit prefectures of Iwate and Miyagi, the earthquake produced 15 new landslide-dammed lakes; a phenomenon common when the earthquake hypocenter is within inland areas. In our last study, we demonstrated that interferometric SAR (InSAR) technique can detect surface displacements within centimeter accuracy and create detailed three-dimensional terrain information. In this study, we developed a new methodology to detect landslide-dammed lakes using Digital Drainage Models (DDMs) generated from the DEM's cre-ated with InSAR data. Using our technique, small scale topographical change was detected by comparing pre-earthquake DEM's such as created from the Shuttle Radar Topographic Mission (SRTM) data and post-earthquake DEM's created from the Advanced Land Observing System (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data. Pre-and post-earthquake changes in the drainage networks were detected by comparing DDM features derived from an existing DEM to DDM features derived from a post-earthquake DEM created from ALOS InSAR data. It was verified that landslide-dammed lakes were detected specifically in the area where drainage network with more than three of the river-order computed from DDM's shifted before and after the earthquake. Thus, InSAR DEM generated from ALOS/PALSAR can provide timely and useful spatial information for detecting landslide-dammed lakes.

  19. Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

    USGS Publications Warehouse

    Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

    2015-01-01

    Results from the simulated dam failure of the Lago de Matrullas Dam using the HEC–RAS model for the 6- and 24-hour PMP events showed peak discharges at the dam of 3,149.33 and 3,604.70 m3/s, respectively. Dam failure during the 100-year-recurrence, 24-hour rainfall event resulted in a peak discharge of 2,103.12 m3/s directly downstream from the dam. Dam failure under sunny day conditions produced a peak discharge of 1,695.91 m3/s at the dam assuming the antecedent lake level was at the morning-glory spillway invert elevation. Flood-inundation maps prepared as part of the study depict the flood extent and provide valuable information for preparing an Emergency Action Plan. Results of the failure analysis indicate that a failure of the Lago de Matrullas Dam could cause flooding to many of the inhabited areas along stream banks from the Lago de Matrullas Dam to the mouth of the Río Grande de Manatí. Among the areas most affected are the low-lying regions in the vicinity of the towns of Ciales, Manatí, and Barceloneta. The delineation of the flood boundaries near the town of Barceloneta considered the effects of a levee constructed during 2000 at Barceloneta in the flood plain of the Río Grande de Manatí to provide protection against flooding to the near-by low-lying populated areas. The results showed overtopping can be expected in the aforementioned levee during 6- and 24-hour probable-maximum-precipitation dam failure scenarios. No overtopping of the levee was simulated, however, during dam failure scenarios under the 100-year recurrence, 24-hour rainfall event or sunny day conditions.

  20. A visual resource management study of alternative dams, reservoirs and highway and transmission line corridors near Copper Creek, Washington

    Treesearch

    John Ady; Brian A. Gray; Grant R. Jones

    1979-01-01

    Three alternative dams have been considered by Seattle City Light for the Skagit River Narrows in the North Cascades National Recreation Area, Washington. The authors assessed the area's existing visual resources, identified three alternative highway and transmission line realignments, evaluated changes in visual character and quality for 13 different combinations...

  1. Homing and movement of yellow-phase American eels in freshwater ponds

    USGS Publications Warehouse

    Lamothe, P.J.; Gallagher, M.; Chivers, D.P.; Moring, J.R.

    2000-01-01

    Ten yellow-phase American eels, Anguilla rostrata, were captured from Hammond Pond, a small freshwater pond located in central Maine, U.S.A. The eels were implanted with radio transmitters and released into nearby Hermon Pond. At the same time, 10 eels were captured from Hermon Pond, implanted with radio transmitters and returned to Hermon Pond to serve as a control group. The two ponds are connected by a 1.6km section of Souadabscook Stream. We tracked the 20 eels over the 90-day duration of the experiment. Four of the ten displaced eels returned to their home pond. None of the control fish were located outside of their home pond during the study. Three of the four eels that successfully returned to their home pond did so under the darkness of the new moon and the fourth made the journey during the first quarter moon phase. Location data showed that translocated and native eels tended to occupy different areas of Hermon Pond. This study provides evidence of homing behavior in American eels living in small freshwater ponds and indications that homing activity may be linked to lunar cycle.

  2. Fate of endocrine disrupters in waste stabilization pond systems.

    PubMed

    Gomez, E; Wang, X; Dagnino, S; Leclercq, M; Escande, A; Casellas, C; Picot, B; Fenet, H

    2007-01-01

    The performance in the removal of estrogenicity from wastewater was studied in three wastewater treatment plants (WWTPs). Different treatment processes were evaluated: stabilization ponds and trickling filter. Sampling was performed from the input to the output of the treatment systems. The total estrogenic activity was determined with MCF-7-derived cell lines which express the endogenous estrogen receptor alpha. The two wastewater stabilization ponds with long retention time had high removal of estrogenicity (90% to 95%). Trickling filters despite being effective at removing organic load were less effective in removing estrogenicity (42%), and post tertiary ponds enhanced estrogenicity removal.

  3. Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia

    NASA Astrophysics Data System (ADS)

    Apukhtina, Olga B.; Kamenetsky, Vadim S.; Ehrig, Kathy; Kamenetsky, Maya B.; McPhie, Jocelyn; Maas, Roland; Meffre, Sebastien; Goemann, Karsten; Rodemann, Thomas; Cook, Nigel J.; Ciobanu, Cristiana L.

    2016-01-01

    An assemblage of magnetite and apatite is common worldwide in different ore deposit types, including disparate members of the iron-oxide copper-gold (IOCG) clan. The Kiruna-type iron oxide-apatite deposits, a subtype of the IOCG family, are recognized as economic targets as well. A wide range of competing genetic models exists for magnetite-apatite deposits, including magmatic, magmatic-hydrothermal, hydrothermal(-metasomatic), and sedimentary(-exhalative). The sources and mechanisms of transport and deposition of Fe and P remain highly debatable. This study reports petrographic and geochemical features of the magnetite-apatite-rich vein assemblages in the dolerite dykes of the Gairdner Dyke Swarm (~0.82 Ga) that intruded the Roxby Downs Granite (~0.59 Ga), the host of the supergiant Olympic Dam IOCG deposit. These symmetrical, only few mm narrow veins are prevalent in such dykes and comprise besides usually colloform magnetite and prismatic apatite also further minerals (e.g., calcite, quartz). The genetic relationships between the veins and host dolerite are implied based on alteration in the immediate vicinity (~4 mm) of the veins. In particular, Ti-magnetite-ilmenite is partially to completely transformed to titanite and magmatic apatite disappears. We conclude that the mafic dykes were a local source of Fe and P re-concentrated in the magnetite-apatite veins. Uranium-Pb ages for vein apatite and titanite associated with the vein in this case study suggest that alteration of the dolerite and healing of the fractures occurred shortly after dyke emplacement. We propose that in this particular case the origin of the magnetite-apatite assemblage is clearly related to hydrothermal alteration of the host mafic magmatic rocks.

  4. Sunlight and the 5-year incidence of early age-related maculopathy: the beaver dam eye study.

    PubMed

    Cruickshanks, K J; Klein, R; Klein, B E; Nondahl, D M

    2001-02-01

    To investigate the relation of sunlight exposure and indicators of sun sensitivity with the 5-year incidence of early age-related maculopathy (ARM). Longitudinal, population-based study. Participants (aged 43-86 years at baseline) in the Beaver Dam Eye Study were reexamined from 1993 to 1995, 5 years after the baseline examination. Questionnaire data about sunlight exposure and sun sensitivity were obtained at baseline. Additional information about earlier life patterns of exposure was ascertained at follow-up. Stereoscopic color fundus photographs were graded to determine the presence of ARM at the 5-year follow-up in eyes free from signs of early ARM at the baseline examination. Leisure time spent outdoors while persons were teenagers (aged 13-19 years) and in their 30s (aged 30-39 years) was significantly associated with the risk of early ARM (odds ratio, 2.09; 95% confidence interval, 1.19-3.65). There was a slight, but nonsignificant, protective effect associated with use of hats and sunglasses while persons were teenagers and in their 30s (odds ratio, 0.72; 95% confidence interval, 0.50-1.03). People with red or blond hair were slightly more likely to develop early ARM than people with darker hair (odds ratio, 1.33; 95% confidence interval, 0.97-1.83). There were no associations between estimated ambient UV-B exposure or markers of sun sensitivity and the incidence of early ARM. Exposure to sunlight may be associated with the development of early ARM.

  5. The use of rubber dam among Czech dental practitioners.

    PubMed

    Kapitán, Martin; Sustová, Zdenka

    2011-01-01

    Rubber dam is considered an ideal device for tooth isolation. Nevertheless, its usage is quite rare in the Czech Republic. The aim of this study was: firstly, to gather and evaluate information regarding the use of rubber dam by dentists in the Czech Republic and to compare it with other countries; secondly to find out whether there are any influencing factors as to rubber dam usage; and finally to find out frequency of rubber dam use separately in endodontic treatment and in placing fillings of different materials. A questionnaire-based survey was conducted. Dentists filled in the questionnaires during dental conventions, educational events, conferences and congresses. Rubber dam was routinely used by less than eight per cent of the respondents (n = 35); less than twenty-two per cent of the respondents (n = 97) used rubber dam occasionally, and more than seventy per cent of the respondents (n = 317) has never use it. The results showed that rubber dam is not used frequently in the Czech Republic. If rubber dam is used, then it is typically for endodontic treatment or composite fillings. There were several factors with a statistically significant influence on the usage of rubber dam, such as gender, length of professional career, percentage of direct payments, previous experience in using rubber dam, and undergraduate training in rubber dam use.

  6. Small thaw ponds: an unaccounted source of methane in the Canadian high Arctic.

    PubMed

    Negandhi, Karita; Laurion, Isabelle; Whiticar, Michael J; Galand, Pierre E; Xu, Xiaomei; Lovejoy, Connie

    2013-01-01

    Thawing permafrost in the Canadian Arctic tundra leads to peat erosion and slumping in narrow and shallow runnel ponds that surround more commonly studied polygonal ponds. Here we compared the methane production between runnel and polygonal ponds using stable isotope ratios, ¹⁴C signatures, and investigated potential methanogenic communities through high-throughput sequencing archaeal 16S rRNA genes. We found that runnel ponds had significantly higher methane and carbon dioxide emissions, produced from a slightly larger fraction of old carbon, compared to polygonal ponds. The methane stable isotopic signature indicated production through acetoclastic methanogenesis, but gene signatures from acetoclastic and hydrogenotrophic methanogenic Archaea were detected in both polygonal and runnel ponds. We conclude that runnel ponds represent a source of methane from potentially older C, and that they contain methanogenic communities able to use diverse sources of carbon, increasing the risk of augmented methane release under a warmer climate.

  7. Small Thaw Ponds: An Unaccounted Source of Methane in the Canadian High Arctic

    PubMed Central

    Negandhi, Karita; Laurion, Isabelle; Whiticar, Michael J.; Galand, Pierre E.; Xu, Xiaomei; Lovejoy, Connie

    2013-01-01

    Thawing permafrost in the Canadian Arctic tundra leads to peat erosion and slumping in narrow and shallow runnel ponds that surround more commonly studied polygonal ponds. Here we compared the methane production between runnel and polygonal ponds using stable isotope ratios, 14C signatures, and investigated potential methanogenic communities through high-throughput sequencing archaeal 16S rRNA genes. We found that runnel ponds had significantly higher methane and carbon dioxide emissions, produced from a slightly larger fraction of old carbon, compared to polygonal ponds. The methane stable isotopic signature indicated production through acetoclastic methanogenesis, but gene signatures from acetoclastic and hydrogenotrophic methanogenic Archaea were detected in both polygonal and runnel ponds. We conclude that runnel ponds represent a source of methane from potentially older C, and that they contain methanogenic communities able to use diverse sources of carbon, increasing the risk of augmented methane release under a warmer climate. PMID:24236014

  8. A review of virus removal in wastewater treatment pond systems.

    PubMed

    Verbyla, Matthew E; Mihelcic, James R

    2015-03-15

    Wastewater treatment ponds (lagoons) are one of the most common types of technologies used for wastewater management worldwide, especially in small cities and towns. They are particularly well-suited for systems where the effluent is reused for irrigation. However, the efficiency of virus removal in wastewater treatment pond systems is not very well understood. The main objective of this paper is to critically review the major findings related to virus removal in wastewater treatment pond systems and to statistically analyze results reported in the literature from field studies on virus removal in these systems. A comprehensive analysis of virus removal reported in the literature from 71 different wastewater treatment pond systems reveals only a weak to moderate correlation of virus removal with theoretical hydraulic retention time. On average, one log10 reduction of viruses was achieved for every 14.5-20.9 days of retention, but the 95th percentile value of the data analyzed was 54 days. The mechanisms responsible for virus removal in wastewater treatment ponds were also reviewed. One recent finding is that sedimentation may not be a significant virus removal mechanism in some wastewater ponds. Recent research has also revealed that direct and indirect sunlight-mediated mechanisms are not only dependent on pond water chemistry and optics, but also on the characteristics of the virus and its genome. MS2 coliphage is considered to be the best surrogate for studying sunlight disinfection in ponds. The interaction of viruses with particles, with other microorganisms, and with macroinvertebrates in wastewater treatment ponds has not been extensively studied. It is also unclear whether virus internalization by higher trophic-level organisms has a protective or a detrimental effect on virus viability and transport in pond systems. Similarly, the impact of virus-particle associations on sunlight disinfection in ponds is not well understood. Future research should focus on

  9. Disentangling natural and anthropogenic influences on Patagonian pond water quality.

    PubMed

    Epele, Luis B; Manzo, Luz M; Grech, Marta G; Macchi, Pablo; Claverie, Alfredo Ñ; Lagomarsino, Leonardo; Miserendino, M Laura

    2017-09-20

    The water quality of wetlands is governed not only by natural variability in hydrology and other factors, but also by anthropogenic activities. Patagonia is a vast sparsely-populated in which ponds are a key component of rural and urban landscapes because they provide several ecosystem services such as habitat for wildlife and watering for livestock. Integrating field-based and geospatial data of 109 ponds sampled across the region, we identified spatial trends and assessed the effects of anthropogenic and natural factors in pond water quality. The studied ponds were generally shallow, well oxygenated, with maximum nutrient values reported in sites used for livestock breeding. TN:TP ratio values were lower than 14 in >90% of the ponds, indicating nitrogen limitation. Water conductivity decreased from de east to the west, meanwhile pH and dissolved oxygen varied associated with the latitude. To assess Patagonian ponds water status we recommend the measure of total suspended solids and total nitrogen in the water, and evaluate the mallín (wetland vegetation) coverage in a 100m radius from the pond, since those features were significantly influenced by livestock land use. To evaluate the relative importance of natural variability and anthropogenic influences as driving factors of water quality we performed three generalized linear models (GLM) that encompassed the hydrology, hydroperiod and biome (to represent natural influences), and land use (to represent anthropogenic influences) as fixed effects. Our results revealed that at the Patagonian scale, ponds water quality would be strongly dependent on natural gradients. We synthetized spatial patterns of Patagonian pond water quality, and disentangled natural and anthropic factors finding that the dominant environmental influence is rainfall gradient. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. 1D and 2D urban dam-break flood modelling in Istanbul, Turkey

    NASA Astrophysics Data System (ADS)

    Ozdemir, Hasan; Neal, Jeffrey; Bates, Paul; Döker, Fatih

    2014-05-01

    Urban flood events are increasing in frequency and severity as a consequence of several factors such as reduced infiltration capacities due to continued watershed development, increased construction in flood prone areas due to population growth, the possible amplification of rainfall intensity due to climate change, sea level rise which threatens coastal development, and poorly engineered flood control infrastructure (Gallegos et al., 2009). These factors will contribute to increased urban flood risk in the future, and as a result improved modelling of urban flooding according to different causative factor has been identified as a research priority (Gallegos et al., 2009; Ozdemir et al. 2013). The flooding disaster caused by dam failures is always a threat against lives and properties especially in urban environments. Therefore, the prediction of dynamics of dam-break flows plays a vital role in the forecast and evaluation of flooding disasters, and is of long-standing interest for researchers. Flooding occurred on the Ayamama River (Istanbul-Turkey) due to high intensity rainfall and dam-breaching of Ata Pond in 9th September 2009. The settlements, industrial areas and transportation system on the floodplain of the Ayamama River were inundated. Therefore, 32 people were dead and millions of Euros economic loses were occurred. The aim of this study is 1 and 2-Dimensional flood modelling of the Ata Pond breaching using HEC-RAS and LISFLOOD-Roe models and comparison of the model results using the real flood extent. The HEC-RAS model solves the full 1-D Saint Venant equations for unsteady open channel flow whereas LISFLOOD-Roe is the 2-D shallow water model which calculates the flow according to the complete Saint Venant formulation (Villanueva and Wright, 2006; Neal et al., 2011). The model consists a shock capturing Godunov-type scheme based on the Roe Riemann solver (Roe, 1981). 3 m high resolution Digital Surface Model (DSM), natural characteristics of the pond

  11. Quantifying and Generalizing Hydrologic Responses to Dam Regulation using a Statistical Modeling Approach

    SciTech Connect

    McManamay, Ryan A

    2014-01-01

    Despite the ubiquitous existence of dams within riverscapes, much of our knowledge about dams and their environmental effects remains context-specific. Hydrology, more than any other environmental variable, has been studied in great detail with regard to dam regulation. While much progress has been made in generalizing the hydrologic effects of regulation by large dams, many aspects of hydrology show site-specific fidelity to dam operations, small dams (including diversions), and regional hydrologic regimes. A statistical modeling framework is presented to quantify and generalize hydrologic responses to varying degrees of dam regulation. Specifically, the objectives were to 1) compare the effects of local versus cumulative dam regulation, 2) determine the importance of different regional hydrologic regimes in influencing hydrologic responses to dams, and 3) evaluate how different regulation contexts lead to error in predicting hydrologic responses to dams. Overall, model performance was poor in quantifying the magnitude of hydrologic responses, but performance was sufficient in classifying hydrologic responses as negative or positive. Responses of some hydrologic indices to dam regulation were highly dependent upon hydrologic class membership and the purpose of the dam. The opposing coefficients between local and cumulative-dam predictors suggested that hydrologic responses to cumulative dam regulation are complex, and predicting the hydrology downstream of individual dams, as opposed to multiple dams, may be more easy accomplished using statistical approaches. Results also suggested that particular contexts, including multipurpose dams, high cumulative regulation by multiple dams, diversions, close proximity to dams, and certain hydrologic classes are all sources of increased error when predicting hydrologic responses to dams. Statistical models, such as the ones presented herein, show promise in their ability to model the effects of dam regulation effects at

  12. Lethal and sublethal effects of embryonic and larval exposure of Hyla versicolor to Stormwater pond sediments.

    PubMed

    Brand, Adrianne B; Snodgrass, Joel W; Gallagher, Matthew T; Casey, Ryan E; Van Meter, Robin

    2010-02-01

    Stormwater ponds are common features of modern stormwater management practices. Stormwater ponds often retain standing water for extended periods of time, develop vegetative characteristics similar to natural wetlands, and attract wildlife. However, because stormwater ponds are designed to capture pollutants, wildlife that utilize ponds might be exposed to pollutants and suffer toxicological effects. To investigate the toxicity of stormwater pond sediments to Hyla versicolor, an anuran commonly found using retention ponds for breeding, we exposed embryos and larvae to sediments in laboratory microcosms. Exposure to pond sediments reduced survival of embryos by approximately 50% but did not affect larval survival. Larvae exposed to stormwater pond sediment developed significantly faster (x = 39 days compared to 42 days; p = 0.005) and were significantly larger at metamorphosis (x = 0.49 g compared to 0.36 g; p < 0.001) than controls that were exposed to clean sand. Substantial amounts (712-2215 mg/l) of chloride leached from pond sediments into the water column of treatment microcosms; subsequently, survival of embryos was negatively correlated (r (2) = 0.50; p < 0.001) with water conductivity during development. Our results, along with the limited number of other toxicological studies of stormwater ponds, suggest that road salt contributes to the degradation of stormwater pond habitat quality for amphibian reproduction and that future research should focus on understanding interactions among road salts and other pollutants and stressors characteristic of urban environments.

  13. Fine-scale urbanization affects Odonata species diversity in ponds of a megacity (Paris, France)

    NASA Astrophysics Data System (ADS)

    Jeanmougin, Martin; Leprieur, Fabien; Loïs, Grégoire; Clergeau, Philippe

    2014-08-01

    Current developments in urban ecology include very few studies focused on pond ecosystems, though ponds are recognized as biodiversity hotspots. Using Odonata as an indicator model, we explored changes in species composition in ponds localized along an urban gradient of a megacity (Paris, France). We then assessed the relative importance of local- and landscape-scale variables in shaping Odonata α-diversity patterns using a model-averaging approach. Analyses were performed for adult (A) and adult plus exuviae (AE) census data. At 26 ponds, we recorded 657 adults and 815 exuviae belonging to 17 Odonata species. The results showed that the Odonata species assemblage composition was not determined by pond localization along the urban gradient. Similarly, pond characteristics were found to be similar among urban, suburban and periurban ponds. The analyses of AE census data revealed that fine-scale urbanization (i.e., increased density of buildings surrounding ponds) negatively affects Odonata α-diversity. In contrast, pond localization along the urban gradient weakly explained the α-diversity patterns. Several local-scale variables, such as the coverage of submerged macrophytes, were found to be significant drivers of Odonata α-diversity. Together, these results show that the degree of urbanization around ponds must be considered instead of pond localization along the urban gradient when assessing the potential impacts of urbanization on Odonata species diversity. This work also indicates the importance of exuviae sampling in understanding the response of Odonata to urbanization.

  14. Investigation of the environmental impacts of sedimentation in Anzali Pond

    NASA Astrophysics Data System (ADS)

    Barmal, Milad; Neshaei, Seyed Ahmad; Farzan, Niloofar

    2016-04-01

    Anzali harbor is the most essential transportation pole between Iran and other countries of the Caspian Sea basin. Anzali pond is an important ecosystem in the region due to its unique plant and animal species. In order to determine the effects of interaction between pond and sea, a series of in-depth studies and analysis on the pattern of sedimentation in Anzali harbor and pond were performed. The study area is Anzali harbor and pond which is located in southwest of the Caspian Sea in Iran. In recent years the economical importance and improvement program of this region has devoted many scientists and authorities attention to itself. In this paper, researches on environmental impact by sediment and pollution in this zone are performed. Analysis indicates that by disposal of sediment and pollution in this area, the physical and chemical quality of water has declined. Some practical suggestions are made to improve the quality of the studied region in terms of environmental aspects.

  15. Sustainability of dams-an evaluation approach

    NASA Astrophysics Data System (ADS)

    Petersson, E.

    2003-04-01

    Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the

  16. Farmed areas predict the distribution of amphibian ponds in a traditional rural landscape.

    PubMed

    Hartel, Tibor; von Wehrden, Henrik

    2013-01-01

    Traditional rural landscapes of Eastern Europe are undergoing major changes due to agricultural intensification, land abandonment, change in agricultural practices and infrastructural development. Small man-made ponds are important yet vulnerable components of rural landscapes. Despite their important role for biodiversity, these ponds tend to be excluded from conservation strategies. Our study was conducted in a traditional rural landscape in Eastern Europe. The aim of this study is twofold: (i) to model the distribution of four major man-made pond types and (ii) to present the importance of man-made ponds for the endangered Yellow Bellied Toad (Bombina variegata) and the Common Toad (Bufo bufo). Six environmental variables were used to model pond distribution: Corine landcover, the heterogeneity of the landcover, slope, road distance, distance to closest village and the human population density. Land cover heterogeneity was the most important driver for the distribution of fishponds. Areas used for agriculture with significant areas of natural vegetation were the most important predictors for the distribution of temporary ponds. In addition, areas covered by transitional woodland and scrub were important for the open cattle ponds. Bombina variegata was found predominantly in the temporary ponds (e.g. ponds created by cattle and buffalo, dirt road ponds and concrete ponds created for livestock drinking) and Bufo bufo in fishponds. Our Maxent models revealed that the highest probability of occurrence for amphibian ponds was in areas used as farmland. The traditional farming practices combined with a low level of infrastructure development produces a large number of amphibian ponds. The challenge is to harmonize economic development and the maintenance of high densities of ponds in these traditional rural landscapes.

  17. Farmed Areas Predict the Distribution of Amphibian Ponds in a Traditional Rural Landscape

    PubMed Central

    Hartel, Tibor; von Wehrden, Henrik

    2013-01-01

    Background Traditional rural landscapes of Eastern Europe are undergoing major changes due to agricultural intensification, land abandonment, change in agricultural practices and infrastructural development. Small man-made ponds are important yet vulnerable components of rural landscapes. Despite their important role for biodiversity, these ponds tend to be excluded from conservation strategies. Methodology/Findings Our study was conducted in a traditional rural landscape in Eastern Europe. The aim of this study is twofold: (i) to model the distribution of four major man-made pond types and (ii) to present the importance of man-made ponds for the endangered Yellow Bellied Toad (Bombina variegata) and the Common Toad (Bufo bufo). Six environmental variables were used to model pond distribution: Corine landcover, the heterogeneity of the landcover, slope, road distance, distance to closest village and the human population density. Land cover heterogeneity was the most important driver for the distribution of fishponds. Areas used for agriculture with significant areas of natural vegetation were the most important predictors for the distribution of temporary ponds. In addition, areas covered by transitional woodland and scrub were important for the open cattle ponds. Bombina variegata was found predominantly in the temporary ponds (e.g. ponds created by cattle and buffalo, dirt road ponds and concrete ponds created for livestock drinking) and Bufo bufo in fishponds. Conclusions/Significance Our Maxent models revealed that the highest probability of occurrence for amphibian ponds was in areas used as farmland. The traditional farming practices combined with a low level of infrastructure development produces a large number of amphibian ponds. The challenge is to harmonize economic development and the maintenance of high densities of ponds in these traditional rural landscapes. PMID:23704928

  18. Pond Ecology in the Classroom.

    ERIC Educational Resources Information Center

    Kneidl, Sally Stenhouse

    1993-01-01

    Describes activities with organisms from freshwater ponds and ditches. Several experiments involve predation, some involve habitat choices, and one addressees the role of sunlight in supporting plant-eating animals. (PR)

  19. Pond Ecology in the Classroom.

    ERIC Educational Resources Information Center

    Kneidl, Sally Stenhouse

    1993-01-01

    Describes activities with organisms from freshwater ponds and ditches. Several experiments involve predation, some involve habitat choices, and one addressees the role of sunlight in supporting plant-eating animals. (PR)

  20. Hydrological modeling of stream flow in small Mediterranean dams and impact of climate change : case study of wadi Rmel catchment

    NASA Astrophysics Data System (ADS)

    Habaieb, Hamadi; Hermassi, Taoufik; Moncef Masmoudi, Mohamed; Ben Mechlia, Nétij

    2015-04-01

    Northern Tunisia is characterized by a semi-arid climate with an irregular and high spatial variability of rainfall. This situation is expected to aggravate under the expected increase of temperature and modification of rainfall regime predicted by most climate models for the Mediterranean region. Water is a major limiting factor for agriculture in Tunisia and mobilization of surface water resources is approaching its maximum. Dams are installed on almost all large watersheds and concerned also medium size and small ones. Hydrological functioning of such structures and their capacity to satisfy user's demand under the changing climate will be addressed using simple models and results will be discussed in this paper. The small catchment of Wadi Rmel is considered here for methodological development. This watershed (675 Km2) is situated in North-East Tunisia with average annual rainfall of 420 mm and was equipped in 1998 with a small dam. Data on rainfall collected at 12 rainfall stations during the period 1908 - 2012 are analyzed and used to build a coherent series of monthly rainfalls and spatially averaged on the watershed by the Thiessen method. In a second step, rainfall-runoff modeling was used to estimate runoff and water budget of the dam. Tow rainfall-runoff models GR2M and SWAT were considered and evaluated when using i) the rainfall observed at the dam and ii) the average rainfall on the watershed. The observed and simulated level in the dam were compared for both models and situations. Results showed that taking into account the spatial distribution of rainfall improved the simulation of stream flows and that SWAT model performs better than GR2M. The use of such models to make prediction of stream flow using downscaled climatic data from GCM will be discussed. Analysis of the results considering tow standardized sets of future greenhouse gas emissions used by the General Circulation Models for the IPCC 5th approximation RCP4.5 and RCP8.5 and three future